Methods and systems for monitoring a service provided over a packet-switched network

ABSTRACT

Methods and systems for monitoring a service provided over a packet-switched network, such as an Internet Protocol television (IPTV) service, an Internet access service, or a voice-over-Internet-Protocol (VoIP) telephony service. Various parameters related to the service (e.g., parameters indicative of packet loss, packet corruption or other packet error) are determined and used to assess various aspects of the service and/or network over which the service is delivered, including a quality of experience (QoE) of subscribers.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No. 13/809,715 filed on Jan. 11, 2013, which was a National Phase Entry under 35 U.S.C. 371 of International PCT Patent Application Serial No. PCT/CA2011/000815 filed on Jul. 12, 2011, designating the United States, and which claims the benefit of U.S. Provisional Patent Application Ser. No. 61/363,441 filed on Jul. 12, 2010 and the benefit of U.S. Provisional Patent Application Ser. No. 61/391,974 filed on Oct. 11, 2010. The contents of the aforementioned applications are incorporated by reference herein.

FIELD OF THE INVENTION

The invention relates generally to services delivered over packet-switched networks, such as Internet Protocol television (IPTV), Internet access, and voice-over-Internet-Protocol (VoIP) telephony services, and more particularly to methods and systems for monitoring such services.

BACKGROUND

Various services, including Internet access, voice-over-Internet-Protocol (VoIP) telephony, and Internet Protocol television (IPTV), are now being provided over packet-switched networks.

Subscribers to such services enjoy certain advantages, such as interactive features and/or other additional functionality, which they may not find in corresponding services provided over traditional networks (e.g., the public switched telephone network (PSTN), cable television, etc.). However, these services are also susceptible to various issues which can create service impairments affecting a subscriber's quality of experience (QoE). For example, a subscriber to an IPTV service may experience pixelation, screen freezing, set-top box crashes, outages, or other impairments, a subscriber to a VoIP telephony service may experience poor voice quality, dropped calls, or other impairments, etc.

While certain techniques have been used by service providers in an attempt to mitigate such service impairments, there remains a need for solutions directed to monitoring these services, including monitoring a subscriber's quality of experience and/or a network's performance in respect of such services.

SUMMARY OF THE INVENTION

According to an aspect of the invention, there is provided a method of monitoring performance of a system that comprises a gateway connected to an appliance running a media application. The media application is configured to detect gaps between downstream packets received from the gateway and to issue to a head-end server a request for retransmission of a missing downstream packet. The method comprises: determining a first parameter indicative of an incidence of upstream packets intended for an access network having been discarded by the gateway without having been sent to the access network; determining a second parameter indicative of an incidence of gaps between downstream packets received by the media application from the gateway; determining, based on at least the first parameter and the second parameter, a compound parameter indicative of a likelihood that a request for retransmission issued by the media application will not reach the head-end server; and recording a log of the compound parameter on a storage medium.

According to another aspect of the invention, there is provided a method of monitoring performance of a system that comprises a gateway connected to an appliance running a media application. The media application is configured to detect gaps between downstream packets received from the gateway and to issue to a head-end server a request for retransmission of a missing downstream packet unless the missing downstream packet falls within a gap that exceeds a threshold size. The method comprises: determining a first parameter indicative of an incidence of downstream packets intended for the media application having been discarded by the gateway without having been sent to the media application; determining a second parameter indicative of an incidence of gaps between downstream packets received by the media application from the gateway; determining, based on at least the first parameter and the second parameter, a compound parameter indicative of a likelihood that a gap detected by the media application will have a size exceeding the threshold size; and recording a log of the compound parameter on a storage medium.

According to another aspect of the invention, there is provided a method of monitoring performance of a system that comprises a gateway connected to an appliance running a media application. The media application is configured to detect gaps between downstream packets received from the gateway and to issue to a head-end server a request for retransmission of a missing downstream packet unless the missing downstream packet falls within a gap that exceeds a threshold size. The method comprises: determining a first parameter indicative of an incidence of downstream packets having been detected as corrupted; determining a second parameter indicative of an incidence of gaps between downstream packets received by the media application from the gateway; determining, based on at least the first parameter and the second parameter, a compound parameter indicative of a likelihood that a gap detected by the media application will have a size exceeding the threshold size; and recording a log of the compound parameter on a storage medium.

According to another aspect of the invention, there is provided a method of monitoring performance of a system that comprises a gateway connected to at least one appliance running a plurality of applications including a media application and at least one second application. The media application is configured to detect gaps between downstream packets received from the gateway and to issue to a head-end server a request for re-transmission of a missing downstream packet. The method comprises: determining a first parameter indicative of an incidence of downstream packets having been detected as corrupted; determining a second parameter indicative of an incidence of gaps between downstream packets received by the media application from the gateway; determining, based on at least the first parameter and the second parameter, a compound parameter indicative of a degree to which packets related to the at least one second application are corrupted; and recording a log of the compound parameter on a storage medium.

According to another aspect of the invention, there is provided a method of monitoring performance of a system that comprises a gateway connected to an appliance running a media application. The media application is configured to detect gaps between downstream packets received from the gateway and to issue to a head-end server a request for retransmission of a missing downstream packet. The method comprises: determining a first parameter indicative of an incidence of upstream packets sent from the gateway to an access network having been detected as corrupted; determining a second parameter indicative of an incidence of gaps between downstream packets received by the media application from the gateway; determining, based on at least the first parameter and the second parameter, a compound parameter indicative of a likelihood that a request for retransmission issued by the media application will not reach the head-end server; and recording a log of the compound parameter on a storage medium.

According to another aspect of the invention, there is provided a method of monitoring performance of a system that comprises a gateway connected to an appliance running a media application. The media application is configured to detect gaps between downstream packets received from the gateway and to issue to a head-end server a request for retransmission of a missing downstream packet. The method comprises: determining a first parameter indicative of an incidence of downstream packets having been detected as corrupted; determining a second parameter indicative of an incidence of fixed-duration intervals containing at least one downstream packet detected as corrupted; determining, based on at least the first parameter and the second parameter, a compound parameter indicative of a rate at which requests for retransmission are issued by the media application; and recording a log of the compound parameter on a storage medium.

According to another aspect of the invention, there is provided a method of monitoring performance of a system that comprises a gateway connected to an appliance running a media application. The media application is configured to detect gaps between downstream packets received from the gateway and to issue to a head-end server a request for retransmission of a missing downstream packet. The method comprises: determining a first parameter indicative of an incidence of downstream packets having been detected as corrupted; determining a second parameter indicative of an incidence of severely errored intervals, a severely errored interval being a fixed-duration interval containing more than a threshold number of downstream packets that are detected as corrupted; determining, based on at least the first parameter and the second parameter, a compound parameter indicative of an incidence of downstream packets having been corrupted outside the severely errored intervals; and recording a log of the compound parameter on a storage medium.

According to another aspect of the invention, there is provided a method of monitoring performance of a system that comprises a gateway connected to an appliance running a media application. The media application is configured to detect gaps between downstream packets received from the gateway and to issue to a head-end server a request for retransmission of a missing downstream packet. The method comprises: determining a first parameter indicative of an incidence of upstream packets sent from the gateway to an access network having been detected as corrupted; determining a second parameter indicative of an incidence of fixed-duration intervals containing at least one upstream packet sent from the gateway that is detected as corrupted; determining, based on at least the first parameter and the second parameter, a compound parameter indicative of a time taken to service an interactive command provided by a user of the media application; and recording a log of the compound parameter on a storage medium.

According to another aspect of the invention, there is provided a method of monitoring performance of a system that comprises a gateway connected to an appliance running a media application. The media application is configured to detect gaps between downstream packets received from the gateway and to issue to a head-end server a request for retransmission of a missing downstream packet. The method comprises: determining a first parameter indicative of an incidence of upstream packets sent from the gateway to an access network having been detected as corrupted; determining a second parameter indicative of an incidence of severely errored intervals, a severely errored interval being a fixed-duration interval containing more than a threshold number of upstream packets sent from the gateway that are detected as corrupted; determining, based on at least the first parameter and the second parameter, a compound parameter indicative of an incidence of upstream packets having been corrupted outside the severely errored intervals; and recording a log of the compound parameter on a storage medium.

According to another aspect of the invention, there is provided a method of monitoring performance of a system that comprises a gateway connected to an appliance running a media application. The media application is configured to detect gaps between downstream packets received from the gateway and to issue to a head-end server a request for retransmission of a missing downstream packet. The method comprises: determining a first parameter indicative of an incidence of missing downstream packets having been retransmitted by the head-end server; determining a second parameter indicative of an incidence of missing downstream packets for which a request for retransmission has been issued; determining, based on at least the first parameter and the second parameter, a compound parameter indicative of a success rate of the head-end server in handling requests for retransmission issued by the media application; and recording a log of the compound parameter on a storage medium.

According to another aspect of the invention, there is provided a method of monitoring performance of a system that comprises a gateway connected to an appliance running a media application. The media application is configured to detect gaps between downstream packets received from the gateway and to issue to a head-end server a request for retransmission of a missing downstream packet. The method comprises: determining a first parameter indicative of an incidence of downstream packets not reaching the media application in time for a content of the media packets to be delivered to a user of the media application; determining a second parameter indicative of an incidence of downstream packets having been detected as corrupted; determining a third parameter indicative of an incidence of downstream packets intended for the media application having been discarded by the gateway without having been sent to the media application; determining, based on at least the first, second and third parameters, a compound parameter indicative of a faultiness of a connection between the gateway and the appliance; and recording a log of the compound parameter on a storage medium.

These and other aspects of the invention will now become apparent to those of ordinary skill in the art upon review of the following description of embodiments of the invention in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

A detailed description of embodiments of the invention is provided below, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 shows an example of a network for providing services, including an Internet Protocol television (IPTV) service, to subscribers in accordance with an embodiment of the invention;

FIG. 2 shows an example of a gateway of a subscriber's end-user equipment;

FIG. 3 shows an example of a set-top box of the subscriber's end-user equipment;

FIG. 4 shows an example of a service monitoring entity of the network;

FIGS. 5 and 6 show an example of a process to determine levels of quality of experience of a subscriber for different periods of time;

FIGS. 7 to 11 show examples of manifestations of a graphical user interface (GUI) of a monitoring tool;

FIG. 12 shows an example of how a user of the monitoring tool can identify a root cause of a subscriber's issue; and

FIG. 13 shows an example of a more detailed network architecture over which the IPTV service can be delivered.

In the drawings, embodiments of the invention are illustrated by way of example. It is to be expressly understood that the description and drawings are only for the purpose of illustrating certain embodiments of the invention and are an aid for understanding. They are not intended to be a definition of the limits of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

FIG. 1 shows an example of a network 10 for providing services to subscribers in accordance with an embodiment of the invention. In this embodiment, one of these services is a television-containing multimedia service which is provided by a service provider (e.g., a telecommunications company, a cable company, etc.) that controls at least part of a packet-switched network 13 over which this service is delivered to subscribers. This control helps to ensure a desired level of quality of service, security, interactivity and reliability for the subscribers. The service provider thus has a relationship with each subscriber of the television-containing multimedia service in order for that subscriber to have the service it provides. Other services which may be provided over the network 10 may include, for example, an Internet access service and a telephone service.

More particularly, in this embodiment, the television-containing multimedia service is an Internet Protocol television (IPTV) service delivered over the packet-switched network 13 which employs Internet Protocol (IP) routing to convey audio, video and control data. The IPTV service includes delivery of television (TV) content comprising TV programs (e.g., live or recorded drama, comedy, news, reality or other TV shows, movies, sporting events, etc.) currently broadcast on various TV channels. In this case, the IPTV service also provides time-shifted TV programming allowing the subscribers to watch TV programs in a time-shifted manner (e.g., a “catch-up” TV feature which replays a TV program broadcast hours or days ago, or a “start-over” TV feature which replays a current TV program from its beginning). In addition to delivery of currently-broadcast TV content, in this case, the IPTV service also includes delivery of other audio/video (A/V) content on-demand, such as movies, TV shows, etc., which are not part of scheduled TV programming but can be selected by the subscribers using a video-on-demand (VOD) feature.

The network 10 comprises an IPTV system 11 which acquires TV and other A/V content, processes (e.g., encodes and/or stores) the acquired content, and distributes the content to the subscribers via packets conveyed over the packet-switched network 13. In this embodiment, the IPTV system 11 comprises a network apparatus 20 that will be referred to as a “super head-end” (SHE) and that is connected to a core network 22, which is also connected to a plurality of network apparatuses 24 ₁-24 _(R) that will be referred to as “video hub offices” or “video head-end offices” (VHOs), each of which is also connected to an access network 26 that is also connected to end-user equipment, including, in this example, end-user equipment 30 ₁-30 _(N) located at subscriber premises 28 ₁-28 _(N) of the subscribers (sometimes referred to as “customer premises equipment” (CPE)).

The SHE 20 comprises suitable hardware and/or software for implementing a plurality of functional entities, including a processing entity 32 and a routing entity 33.

The processing entity 32 is configured to acquire TV and/or other A/V content and process this content for distribution to the subscribers. More particularly, in this embodiment, the processing entity 32 comprises a content acquisition entity 36 which performs a content ingestion process to acquire TV and other A/V content from a plurality of sources of content 34 ₁-34 _(C). For example, a source of content 34 _(x) may comprise an antenna receiving radio broadcast content (e.g., TV programs on national broadcast channels), a cable (e.g., fiber-optic or coaxial) conveying broadcast content (e.g., TV programs on specialty channels), a satellite dish receiving content conveyed by a satellite signal, storage media (e.g., magnetic or optical disks) storing recorded content (e.g., movies or TV shows), or any other source of content (e.g., a wired or wireless link conveying content taken from a live studio). The content acquisition entity 36 may comprise one or more encoders (e.g., for MPEG or WM compression) and one or more servers to acquire the content and put it in a format for distribution to the subscribers. For instance, in this embodiment, IPTV system 11 is implemented using a Microsoft IPTV™ platform and the content acquisition entity 36 comprises one or more acquisition servers, referred to as “A-servers”. In other embodiments, the IPTV system 11 may be implemented using any other suitable platform.

The processing entity 32 may perform other operations in addition to its content acquisition operation. For example, in this embodiment, the processing entity 32 comprises a digital rights management (DRM) entity 42 for encrypting or otherwise processing the acquired content to prevent unauthorized access, copying or conversion to other formats by end-users. As another example, in this embodiment, the processing entity 32 comprises an advertisement entity 43 for inserting advertisements in some of the content distributed to the subscribers. As yet another example, in this embodiment, the processing entity 32 comprises an applications entity 44 for implementing applications that may be invoked by the subscribers (e.g., an electronic program guide (EPG) displaying scheduling information for current and upcoming programming, games or other interactive features, etc.)

Furthermore, in accordance with an embodiment of the invention, and as further discussed later, the processing entity 32 comprises a service monitoring entity 45 configured to collect and analyze data regarding parameters related to the IPTV service provided to the subscribers in order to assess various aspects of the IPTV service, including a quality of experience (QoE) of the subscribers.

In some embodiments, the processing entity 32, including the content acquisition entity 36, the DRM entity 42, the advertisement entity 43, the applications entity 44 and the service monitoring entity 45, may be part of a content management system (CMS) used by the service provider. In other embodiments, one or more components of the processing entity 42 may be part of one or more other systems used by the service provider. For instance, in some cases, the service monitoring entity 45 may be part of a network management system (e.g., Operations Support Systems/Business Support Systems (OSS/BSS)) used by the service provider.

The routing entity 33 is configured to transmit and receive packets pertaining to the IPTV service over the core network 22. For instance, the routing entity 33 may comprise one or more routers or switches. Packets transmitted by the routing entity 33 in a downstream direction (i.e., towards the end-user equipment 30 ₁-30 _(N)) may include packets conveying TV and/or other A/V content for distribution to the subscribers. For example, packets conveying TV content currently being broadcast may be transmitted as multicast streams, while packets conveying content selected on-demand may be transmitted as unicast streams. Packets received by the routing entity 33 in an upstream direction (i.e., towards the SHE 20) may include packets conveying requests or commands made by the subscribers via the end-user equipment 30 ₁-30 _(N) (e.g., TV channel changes, movie selections from the VOD feature, etc). Packets received by the routing entity 33 in the upstream direction may also include packets which convey data regarding parameters related to the IPTV service provided to the subscribers and which are destined for the service monitoring entity 45.

The SHE 20 may serve a relatively large geographical area. For instance, in some embodiments, the SHE 20 may serve at a national level, in which case the broadcast content from the sources of content 34 ₁-34 _(C) may include broadcast content on national TV channels and/or the advertisements inserted by the advertisement entity 43 may be national ads.

The core network 22 comprises high-capacity communication links (e.g., optical fiber links, etc.) which interconnect different components of the network 10, including in this case the SHE 20 and the VHOs 24 ₁-24 _(R).

The VHOs 24 ₁-24 _(R) are geographically distributed in order to deliver the IPTV service to subsets of the subscribers in different regions. In that sense, the VHOs 24 ₁-24 _(R) can viewed as “regional head-ends” acting as relay points between the SHE 20 and the subscribers. For instance, in some embodiments, each of the VHOs 24 ₁-24 _(R) may be used to deliver the IPTV service to between 100,000 and 1,000,000 subscribers.

Each VHO 24 _(x) comprises suitable hardware and/or software for implementing a plurality of functional entities, including a processing entity 46 and a routing entity 47.

The processing entity 46 of the VHO 24 _(x) is configured to distribute TV and/or other A/V content to the subscribers. More particularly, in this embodiment, the processing entity 46 comprises a content distribution entity 48 for delivering content to respective ones of the subscribers over the access network 26. Some content distributed by the content distribution entity 48 is received from the SHE 20 over the core network 22. In addition, in this embodiment, some content distributed by the content distribution entity 48 may be acquired at the VHO 24 _(x) from a plurality of sources of content 49 ₁-49 _(F) such that the VHO 24 _(x) comprises a content acquisition entity 53. For example, a source of content 49 _(x) may comprise an antenna receiving regional radio broadcast content (e.g., TV programs on regional TV channels), a cable conveying regional broadcast content (e.g., TV programs on specialty channels targeted to the regional audience), storage media storing recorded content (e.g., movies or TV shows targeted to the regional audience), or any other source of content. The content acquisition entity 53 may comprise one or more encoders and one or more servers to acquire the content and put it in a format for distribution to the subscribers. For instance, in this embodiment where the IPTV system 11 is implemented using a Microsoft IPTV™ platform, the content acquisition entity 53 comprises one or more “A-servers”.

The content distribution entity 48 comprises one or more distribution servers to distribute the content to the subscribers. More particularly, in this embodiment, the content distribution entity 48 comprises one or more distribution servers configured to distribute TV content received from the SHE 20 and/or acquired by the VHO 24 _(x) to the subscribers. For instance, in this embodiment where the IPTV system 11 is implemented using a Microsoft IPTV™ platform, each of these one or more distribution servers is a “D-server”. Also, in this embodiment, the content distribution entity 48 comprises one or more on-demand servers configured to distribute on-demand content selected by the subscribers (e.g., VOD servers for delivering movies, TV shows or other content on-demand).

The processing entity 46 of the VHO 24 _(x) may perform other operations in addition to its content distribution operation. For example, in this embodiment, the processing entity 46 comprises a DRM entity 62 for encrypting or otherwise processing the content acquired at the VHO 24 _(x) to prevent unauthorized access, copying or conversion to other formats by end-users. As another example, in this embodiment, the processing entity 46 comprises an advertisement entity 60 for inserting advertisements in some of the content distributed to the subscribers. As yet another example, in this embodiment, the processing entity 46 comprises an applications entity 61 for implementing applications that may be invoked by the subscribers (e.g., an electronic program guide (EPG) displaying scheduling information for current and upcoming programming, games and/or other interactive features, etc).

The routing entity 47 of the VHO 24 _(x) is configured to route packets pertaining to the IPTV service over the access network 26 _(x). For instance, the routing entity 33 may comprise one or more routers or switches. Packets transmitted by the routing entity 47 in the downstream direction may include packets conveying TV and/or other A/V content for distribution to the subscribers. Packets transmitted by the routing entity 47 in the upstream direction may include packets conveying requests or commands made by the subscribers (e.g., TV channel changes, movie selections from the VOD feature, etc.). Packets transmitted by the routing entity 47 in the upstream direction may also include packets conveying requests for retransmission of certain packets conveying TV and/or other A/V content that were missing, discarded, corrupted or otherwise not properly received by pieces of equipment of the end-user equipment 30 ₁-30 _(N) at the subscriber premises 28 ₁-28 _(N). Packets transmitted by the routing entity 47 in the upstream direction may also include packets which convey data regarding parameters related to the IPTV service provided to the subscribers and which are destined for the service monitoring entity 45 of the SHE 20.

As mentioned above, the VHO 24 _(x) may be used for delivering the IPTV service to subscribers in a particular region. For instance, in this embodiment, while the SHE 20 is used at a national level, the VHO 24 _(x) is used at a regional level such that the broadcast content from the sources of content 49 ₁-49 _(F) may include broadcast content on regional TV channels and/or the advertisements inserted by the advertisement entity 60 may be regional ads.

The access network 26 (sometimes referred to as the “last mile”) forms a final leg delivering connectivity to subscribers and comprises a plurality of communication links that connect end-user equipment of subscribers to a remainder of the network 10, including, in this example, a plurality of communication links 63 ₁-63 _(N) that reach the end-user equipment 30 ₁-30 _(N) located at the subscriber premises 28 ₁-28 _(N). In this embodiment, the communication links 63 ₁-63 _(N) are connected to an access network apparatus 64. In this example, the access network apparatus 64 is an access multiplexer. More particularly, in this embodiment, each of the communication links 63 ₁-63 _(N) comprises a metallic twisted-pair cable (e.g., a copper twisted-pair cable) and the access multiplexer 64 is a digital subscriber line access multiplexer (DSLAM). For instance, in some embodiments, the access network 26 may implement a fiber-to-the-node or -neighborhood (FUN) architecture such that the DSLAM 64 comprises a FTTN platform (e.g., an Alcatel 7330 Intelligent Services Access Manager (ISAM) Fiber to the Node (FTTN) platform).

The access network 26 also comprises a monitoring entity 58 configured to perform measurements of certain parameters related to the IPTV service provided to the subscribers and to report data regarding these parameters to the service monitoring entity 45, as further discussed later. In some embodiments, the DSLAM 64 and the monitoring entity 58 may be implemented by a common network component. In other embodiments, the DSLAM 64 and the monitoring entity 58 may be implemented by distinct network components linked together by one or more physical links.

The access network 26 may be implemented in various other ways in other embodiments. For example, in some embodiments, the access network 26 may be based on another type of fiber-to-the-x (FTTx) architecture, such as a fiber-to-the-curb (FTTC) architecture, or a fiber-to-the-premises (FTTP) architecture (e.g., fiber-to-the-building (FTTB) or fiber-to-the-house (FTTH) infrastructures) in which case the access multiplexer 64 may be omitted and the communication links 63 ₁-63 _(N) may comprise optical fiber cables leading to optical network terminals (ONTs) that may be part of the end-user equipment 30 ₁-30 _(N) at the subscriber premises 28 ₁-28 _(N). As another example, in some embodiments, each of the communication links 63 ₁-63 _(N) may comprise a coaxial cable instead of a metallic twisted-pair cable or optical fiber cable.

Various network apparatuses of the network 10, including those of the IPTV system 11 (e.g., the SHE 20 and the VHOs 24 ₁-24 _(R)), thus implement a head-end system for communicating with the end-user equipment 30 ₁-30 _(N) at the subscriber premises 28 ₁-28 _(N) to provide the IPTV service and possibly one or more other services (e.g., an Internet access service, a telephone service, etc.). Various servers of the network 10 which communicate with the end-user equipment 30 ₁-30 _(N) at the subscriber premises 28 ₁-28 (e.g., a D-server of the content distribution entity 48) may thus be referred to as “head-end servers”.

While the network 10 has a certain configuration in this embodiment, the network 10 may have various other configurations in other embodiments. For example, in some embodiments, one or more additional network apparatuses, such as a Video Serving Office (VSO), may be provided between the VHO 24 _(x) and the access network 26.

The end-user equipment 30 ₁-30 _(N) located at the subscriber premises 28 ₁-28 _(N) enable the subscribers at these premises to have the IPTV service and possibly one or more other services (e.g., an Internet access service, a telephone service, etc.).

The end-user equipment 30 _(x) located at the subscriber premises 28 _(x) is configured to receive and transmit packets pertaining to the IPTV service over the access network 26 _(x) to allow a user 65 at the subscriber premises 28 _(x) to be presented with TV content and/or other A/V content on a TV set 66. The TV set 66 may be based on any suitable display technology, including cathode ray tube (CRT), a liquid-crystal display (LCD), plasma, or any other type of TV display technology (e.g., Digital Light Processing (DLP) or organic light emitting diode (OLED)). In this embodiment, the end-user equipment 30 _(x) can also receive and transmit packets pertaining to an Internet access service over the access network 26 _(x) to allow the user 65 to browse the Internet on a personal computer 67 (e.g., a desktop computer, a laptop computer, etc.), as well as packets pertaining to a voice-over-IP (VoIP) telephony service over the access network 26 to allow the user 65 to engage in telephone calls using a telephone 68 (e.g., a VoIP phone, a a Plain Old Telephony System (POTS) phone equipped with an analog terminal adapter (ATA), or a softphone).

More particularly, in this embodiment, the end-user equipment 30 _(x) comprises a gateway 69 connected to a set-top box (STB) 70 which is connected to the TV set 66. The STB 70 is an example of an appliance running a media application, namely an IPTV application. In this embodiment, the gateway 69 is also connected to the personal computer 67 and the telephone 68. The personal computer 67 is another example of an appliance running a media application, namely an Internet browser application. The telephone 68 is yet another example of an appliance running a media application, namely a telephony application.

With additional reference to FIG. 2, the gateway 69 comprises suitable hardware and/or software for implementing a plurality of functional entities, including a processing entity 71 and a routing entity 72. The processing entity 71 comprises a modem 73 for modulating analog carrier signals to encode digital information and to demodulate analog carrier signals to decode information they convey. For example, in this embodiment where the communication links 63 _(x) comprises a metallic twisted-pair cable, the modem 73 is a DSL modem. The modem 73 may be of another type in other embodiments (e.g., a cable modem) depending on the nature of the communication link 63 _(x).

The processing entity 71 of the gateway 69 also comprises a monitoring entity 74 configured to perform measurements of certain parameters related to the IPTV service provided to the subscriber at the subscriber premises 28 _(x) and to report data regarding these parameters to the service monitoring entity 45, as further discussed later.

The routing entity 72 of the gateway 69 is configured to route packets pertaining to the IPTV service to and from the STB 70 over a physical communication link (i.e., a wired link or wireless link). For instance, the routing entity 72 may comprise a router, switch or other data forwarding component. Packets transmitted by the routing entity 72 to the STB 70 may include packets conveying TV and/or other A/V content for presentation on the TV set 66. Packets transmitted by the routing entity 72 over the access network 26 may include packets conveying requests or commands made by the user 65 (e.g., TV channel changes, selections of movies from the VOD feature, etc.). Packets transmitted by the routing entity 72 over the access network 26 may also include packets conveying requests for retransmission of certain packets conveying TV and/or other A/V content that were missing, discarded, corrupted or otherwise not properly received by the STB 70. Packets transmitted by the routing entity 72 over the access network may also include packets which convey data regarding parameters related to the IPTV service provided to the subscriber at the subscriber premises 28 _(x) and which are destined for the service monitoring entity 45.

In this embodiment, the routing entity 72 of the gateway 69 is also configured to route data pertaining to the Internet access service to and from the personal computer 67, as well to route signals pertaining to the telephone service to and from the telephone 68 (e.g., via a suitable connector depending on whether the phone 68 is a wired POTS equipped with an ATA, a VoIP phone, etc.)

Thus, in this embodiment, the gateway 69 acts as a center or hub for end-user devices at the subscriber premises 28 _(x). More particularly, in this embodiment the subscriber premises 28 _(x) is a residence and the gateway 69 is a residential gateway (RG) whose functional entities, including the processing entity 71 and the routing entity 72, are integrated into a terminal installed at a suitable location at the residence. In other embodiments, the functional entities of the gateway 69 may be part of two or more distinct devices interconnected to one another via one or more physical links.

The STB 70 comprises suitable hardware and/or software for implementing a plurality of functional entities, including a processing entity 75 and a routing entity 76. The processing entity 75 is configured to process a stream of packets conveying TV and/or other A/V content and received via the routing entity 76 in order to generate A/V signals transmitted to the TV set 66 for presenting the TV and/or other A/V content to the user 65. More particularly, in this embodiment, the processing entity 75 comprises a decoder 77 for decoding packets in the received stream of packets. Also, in this embodiment, the processing entity 75 comprises a DRM entity 78 to decrypt or otherwise process the received packets to undue the effects of the DRM entity 42 of the SHE 20 and/or the DRM entity 62 of the VHO 24 _(x). A program selector 79 extracts a selected program stream corresponding to a selection made by the user 65 and provides the packets of the selected program stream to a demultiplexer 80, which divides them into elementary streams (voice, audio and control) that are supplied to a compositor 81 creating A/V signals transmitted to the TV set 66.

The processing entity 75 of the STB 70 is also configured to detect defects, such as corrupted packets, in the received stream of packets. When possible, the processing entity 75 may correct some of the detected defects in the received stream of packets. For example, in this embodiment, these detection and correction functions may be implemented by the decoder 77 of the processing entity 75.

The processing entity 75 of the STB 70 also comprises a monitoring entity 82 configured to perform measurements of certain parameters related to the IPTV service provided to the subscriber at the subscriber premises 28 _(x) and to report data regarding these parameters to the service monitoring entity 45, as further discussed later.

The routing entity 76 of the STB 70 is configured to route packets pertaining to the IPTV service to and from the gateway 69 over the physical communication link linking these components. For instance, the routing entity 76 may comprise a receiver and a transmitter. Packets received by the routing entity 76 in the downstream direction may include packets conveying TV and/or other A/V content for presentation on the TV set 66. Packets transmitted by the routing entity 76 in the upstream direction may include packets conveying requests or commands made by the user 65 (e.g., TV channel changes, movie selections from the VOD feature, etc.). Packets transmitted by the routing entity 76 in the upstream direction may also include packets conveying requests for retransmission of certain packets conveying TV and/or other A/V content that were missing, discarded, corrupted or otherwise not properly received by the STB 70. Packets transmitted by the routing entity 76 in the upstream direction may also include packets which convey data regarding parameters related to the IPTV service provided to the subscriber at the subscriber premises 28 _(x) and which are destined for the service monitoring entity 45.

Although in this embodiment the STB 70 is connected to the TV set 66, in other embodiments, functional entities corresponding to the processing entity 75 and the routing entity 76 of the STB 70 may be integrated into the TV set 66.

As mentioned previously, in this embodiment, the service monitoring entity 45 is configured to collect and analyze data regarding parameters related to the IPTV service provided to the subscribers in order to assess various aspects of the IPTV service, including the QoE of the subscribers.

Referring additionally to FIG. 4, the service monitoring entity 45 comprises an interface 57 and a processing entity 59. The interface 57 of the service monitoring entity 45 allows data, including data regarding parameters related to the IPTV service provided to the subscribers, to be received and transmitted by the service monitoring entity 45. The processing entity 59 is configured to process data received or to be transmitted via the interface 57. More particularly, in this embodiment, the processing entity 59 comprises an analysis entity 56 for analyzing the data to derive information indicative of the QoE of the subscribers, as well as a database 83 for storing the data and the derived information indicative of the QoE of the subscribers, as further discussed below.

The parameters related to the IPTV service provided to the subscribers, which will be referred to as “IPTV service parameters”, can take on various forms. For instance, Table 1 presents examples of IPTV service parameters that may be considered in this embodiment. Various other examples of IPTV service parameters may be considered in other embodiments.

In Table 1, each line corresponds to a respective IPTV service parameter related to the IPTV service provided to the subscriber at the subscriber premises 28 _(x). The first column indicates a name of the respective IPTV service parameter. The second column indicates one or more sources from which the value of the respective IPTV service parameter is determined. Generally, the value of the respective IPTV service parameter may be determined on a basis of measurements performed by the monitoring entity 82 of the STB 70, the monitoring entity 74 of the residential gateway 69, the monitoring entity 58 of the access network 26, and/or other components (e.g., a D-server of the content distribution entity 48 of the VHO 24 _(x)). In some embodiments, the value of the respective IPTV service parameter may be obtained from a network management system (e.g., an OSS/BSS) used by the service provider and collecting data regarding such measurements. For instance, in this embodiment, the value of the respective IPTV service parameter may be obtained from: a Component Management System (CMS) which collects data regarding measurements performed by components at the subscriber premises 28 _(x), namely the residential gateway 69 and the STB 70 (e.g., a “Snapshot” application on the STB 70); an access network system, in this case an Access Care™ (AC) system by Nortel, which collects data regarding measurements performed by the access network 26 and possibly the end-user equipment 30 _(x) at the subscriber premises 28 _(x) (e.g., the modem 73 (“far end”—FE) may report on packets received, errors, etc., through a communication channel to the DSLAM 64 for record keeping and the DSLAM 64 may perform data reporting and recording for its side (“near end”—NE), and the Access Care system may collect the data from the DSLAM 64 related to the NE and FE and provide it to the service monitoring entity 45); and/or a D-server of the content distribution entity 48 of the VHO 24 _(x). In other embodiments, the value of the respective IPTV service parameter may be obtained based on data polled directly from one or more components, such as the residential gateway 69, the STB 70, etc. The second column may also indicate a frequency at which the value of the respective IPTV service parameter is obtained. For instance, in this case, the value of the respective IPTV service parameter may be obtained every fifteen minutes (i.e., the value is for a period of fifteen minutes) or daily (i.e., the value is for a period of one day). The third column provides a definition of the respective IPTV service parameter. The fourth column provides a technical description of the respective IPTV service parameter. The fourth column indicates an importance of the IPTV service parameter for the IPTV service or insight that the IPTV service parameter can give about the IPTV service.

For example, the IPTV service parameter “DISCARD_PKTS_SENT” refers to the number of packets intended to be sent by the residential gateway 69 to the STB 70 but that have been discarded by the residential gateway 69 instead of being sent to the STB 70. The discarded packets may be packets which have been delayed long enough to be useless. This may be caused, for instance, by shortage of resources or buffer overflow at the residential gateway 69. In this embodiment, the value of the “DISCARD_PKTS_SENT” parameter is obtained every fifteen minutes by the residential gateway 69.

As another example, the discarded packets may result in “gaps”, which can also be referred to as “holes, in the stream of packets received at the STB 70 where the discarded packets would normally have been. At least some of these holes may result in the STB 70 issuing requests for retransmission of the discarded packets by a D-server of the content distribution entity 48 of the VOH 24 _(x). In this example, this applies to a hole at the STB 70 that is not larger than a threshold size (e.g., an interval of time corresponding to a number of consecutive missing packets which would normally occupy the hole). This size may be determined, for instance, by evaluating a maximal number of consecutive packets that can be retransmitted to the STB 70 in time to be reinserted in the stream of packets by the STB 70 (e.g., based on processing speeds of the STB 70 and the residential gateway 69, transmission characteristics of the communication link 63 _(x), and/or any other relevant factor). For example, in this case, a request for retransmission may be issued by the STB 70 when encountering a hole with a size not greater than about 150 ms. For holes greater than 150 ms, the STB 70 does not issue requests for retransmission. When there is a request for retransmission, failure of the D-server to retransmit the discarded packets to the STB 70 in a timely manner may lead to pixilation, screen freeze, etc. In this embodiment, the IPTV service parameter “RETRY_NUMBER”, which refers to the number of holes smaller than 150 ms encountered by the STB 70 during a 15-minute interval, is measured by the D-server as the number of retransmission requests every 15 minutes and is used as the number of holes (“HOLES”) in other IPTV service parameters. In other embodiments, the number of holes (“HOLES”) may be determined from measurements performed by the STB 70 itself. For instance, in some cases, a diagnostic tool implemented by the service monitoring entity 45 may query the STB 70 to obtain the number of holes (“HOLES”) as measured by the STB 70.

As yet another example, error conditions may occur in the downstream direction from the access network 26 to the residential gateway 69 that can cause packets to be corrupted. For instance, packets can be determined to be corrupted when they are determined to have failed an error check performed by the residential gateway 69. In this case, the error check is a cyclic redundancy check (CRC). Other error checking techniques may be used in other cases. In this embodiment, the IPTV service parameter “FE_CV” refers to far end code violations, which is a count of CRC anomalies received by the residential gateway 69 during a 15-minute interval. Depending on their severity, code violations can lead to errored seconds or severely errored seconds and result in retransmission of IPTV packets from a D-Server of the content distribution entity 48 of the VOH 24 _(x) to the STB 70. A high “FE_CV” parameter may lead to visual artifacts such as pixilation or screen freeze and audio impairments such as clipping.

A similar discussion can be made in respect of other ones of the IPTV service parameters listed in Table 1.

TABLE 1 Source/ Technical IPTV Parameter Frequency Definition Description Importance CRASH_COUNT STB Crash Number of IPTV service Log Crashes outage occurs 15 min This is a count of when the set-top crash events box crashes. encountered by the set-top box over a 15-min interval. DISC_RCVD/HOLES CMS| Number of In the event that A value of infinity D-Server Discarded holes are means that either 15 min Packets encountered at all IPTV packets Received divided the set top box, have been by Number of requests for successfully Holes retransmission received at the Discarded from the set-top set-top box (i.e. packets received box may not reach no holes). between the set- the D-Server due A high Discarded top box and the to packets being Packet Residential discarded in the Received-to- Gateway would upstream Holes ratio would indicate direction. increase the congestion or probability of the out-of-order requests for re- packets in the transmission upstream from the set-top direction. box failing to The reach the D- “DISC_RCVD” Server, and (number of result in visual discarded and/or audio packets impairments for received) the IPTV parameter is an customer. example of a The parameter “DISC RCVD/ indicative of an HOLES” incidence of parameter is an upstream example a packets intended compound for the access parameter network 26 indicative of a having been likelihood that a discarded by the request for gateway 69 retransmission without having issued by the been sent to the IPTV application access network running on the 26. STB 70 will not The “HOLES” reach the D- (number of server of the holes) parameter content is an example of distribution entity a parameter 48. indicative of an incidence of gaps between downstream packets received by the IPTV application running on the STB 70 from the gateway 69. DISC_RCVD/REQ CMS| Number of In the event that A value of infinity D-Server Discarded holes are means that either 15 min Packets encountered at all IPTV packets Received divided the set top box, have been by Number of requests for successfully Packets retransmission received at the Requested from the set-top set-top box (i.e. Discarded box may not reach no holes) or the packets received the D-Server due holes are more between the set- to packets being than 150 ms (i.e. top box and the discarded in the no request for re- Residential upstream transmission). Gateway would direction. A high Discarded indicate Packet congestion or Received-to- out-of-order Number of packets in the Packets upstream Requested ratio direction. would increase The the probability of “DISC_RCVD” the requests for (number of re-transmission discarded from the set-top packets box failing to received) reach the D- parameter is an Server, and example of a result in visual parameter and/or audio indicative of an impairments for incidence of the IPTV upstream customer. packets intended The for the access “DISC_RCVD/ network 26 REQ” parameter having been is an example a discarded by the compound gateway 69 parameter without having indicative of a been sent to the likelihood that a access network request for 26. retransmission The “REQ” issued by the (number of IPTV application packets running on the requested) STB 70 will not parameter is an reach the D- example of a server of the parameter content indicative of an distribution entity incidence of gaps 48. between downstream packets received by the IPTV application running on the STB 70 from the gateway 69. DISC_SENT/HOLES CMS| Number of This may be A ratio of 1 would D-Server Discarded caused by strongly suggest 15 min Packets Sent shortage of that the hole(s) divided by resources or encountered at Number of Holes buffer overflow, the set-top box Discarded etc. at the are likely caused packets sent residential by the packets denote that gateway. IPTV being discarded packets to be packets being before being sent sent from the discarded would at the residential residential result in holes at gateway. gateway to the the set-top box. A ratio of less set-top box (i.e. than 1 is possible downstream (e.g. more than direction) are one set-top box discarded/ in the home dropped before watching the being sent. same IPTV The channel). “DISC_SENT” A ratio of greater (number of than 1 is possible discarded (e.g. a large hole packets sent) resulting from parameter is an several packets example of a being discarded parameter by the residential indicative of an gateway). incidence of The downstream “DISC_SENT/ packets intended HOLES” for the IPTV parameter is an application example of a running on the compound STB 70 having parameter been discarded indicative of a by the gateway likelihood that a 69 without having gap detected by been sent to the the IPTV IPTV application application running on the running on the STB 70. STB 70 will have The “HOLES” a size exceeding (number of a threshold size. holes) parameter is an example of a parameter indicative of an incidence of gaps between downstream packets received by the IPTV application running on the STB 70 from the gateway 69. DISC_SENT/REQ CMS| Number of This may be A ratio of 1:1 D-Server Discarded caused by would strongly 15 min Packets Sent shortage of suggest that the divided by resources or hole(s) Number of buffer overflow, encountered at Packets etc. at the the set-top box Requested residential are likely caused Discarded gateway. IPTV by the packets packets sent packets being being discarded denote that discarded would before being sent packets to be result in holes at at the residential sent from the the set-top box, gateway. residential and result in A high ratio of gateway to the requests for re- Discarded set-top box (i.e. transmission of Packet Sent-to- downstream discarded packets Number of direction) are (provided that the Packets discarded/ discarded packets Requested may dropped before has a hole size of be an indication being sent. less than 150 ms). that the holes The caused by the “DISC_SENT” sent packets (number of being discarded discarded are larger than packets sent) 150 ms (i.e. too parameter is an large/no request example of a for parameter retransmission). indicative of an The incidence of “DISC_SENT/ downstream REQ” parameter packets intended is an example of for the IPTV a compound application parameter running on the indicative of a STB 70 having likelihood that a been discarded gap detected by by the gateway the IPTV 69 without having application been sent to the running on the IPTV application STB 70 will have running on the a size exceeding STB 70. a threshold size. The “REQ” (number of packets requested) parameter is an example of a parameter indicative of an incidence of gaps between downstream packets received by the IPTV application running on the STB 70 from the gateway 69. DISCARD_PKTS_RCVD CMS Number of This parameter is Discarded IPTV 15 min Discarded an indication of packets received Packets from the congestion within by the residential set-top box home network, gateway may received by resulting in lead to slow or Residential packets from no response Gateway. home devices during channel Discarded being discarded change, or using packets are by the residential PVR trick modes. packets which gateway arrive out-of- discarded due to order or have unacceptable been delayed delay. long enough to become useless. DISCARD_PKTS_SENT CMS Number of Discarded packets When IPTV 15 min Discarded sent denote that packets are Packets Sent by packets to be sent discarded by the Residential from the residential Gateway. residential gateway instead Discarded gateway to the of being sent to packets are set-top box (i.e. the set-top box, packets which downstream holes will likely have been direction) are result and delayed long discarded/ requests for re- enough to be dropped before transmission to useless; as such, being sent. the D-Server will they are being This may be be generated by discarded caused by the set-top box. instead of sent shortage of Failure for the D- by the residential resources or Server to re- gateway. buffer overflow, transmit these etc. at the discarded residential packets to the gateway. IPTV set-top box in a packets being timely manner discarded would will lead to result in holes at pixilation, screen the set-top box. freeze, etc. ERRORS_RCVD CMS Number of Errors Possible errors High error counts Daily Received by the include CRC in the upstream Residential errors, corrupted direction may Gateway. frames, etc. result in slow This provides a received by the channel change daily count of residential time and/or transmission gateway from the commands to the errors in the set-top box. These PVR being slow upstream errors are likely or unresponsive. direction (i.e. caused by issues received by the with the inside Residential wiring. Gateway). ERRORS_SENT CMS Number of Errors Possible errors IPTV packets Daily Sent by the include CRC containing errors Residential errors, corrupted will result in Gateway frames, etc. requests for re- This provides a detected by the transmission daily count of residential from the set-top errors in the gateway prior to box to the D- IPTV packets sending to the set- Server. If these detected by the top box. packets are not residential retransmitted and gateway. received by the set-top box in time, visual and/or audio impairments will occur. FE_CB AccessCare Far End - This is a count of Corrected Blocks 15 min Corrected Block the number of should not have This is a blocks at the any direct impact measure of the residential on IPTV number of gateway (i.e. customer packets with downstream) experience. errors which which have been have been corrected using corrected in the FEC (forward downstream error correction) direction. during the 15-min interval. FE_CV AccessCare Far End - Code Code violation is Depending on 15 min Violation defined as a count the severity, the This is a of the CRC presence of code measure of anomalies violations leads errors conditions occurring during to errored of the DSL the accumulation seconds or connection in the period (15-min). severely errored downstream Far End Code seconds. direction. Violation refers to Code violations CRC anomalies in the received by the downstream Residential direction results Gateway. in retransmission of IPTV packets from the D- Server to the set- top box. A high CV value in the downstream may lead to visual artefacts such as pixilation or screen freeze and audio impairments such as clipping. FE_CV/FE_ES AccessCare Far End Code This ratio is an A high CV-to-ES 15 min Violations divided indicator of how ratio in the by Far End the Code downstream Errored Seconds Violations in the direction will The “FE_CV” (far downstream likely result in end code direction are frequent packet violations) distributed during retransmissions parameter is an the 15-min between the D- example of a interval. Server and set- parameter top box, with a indicative of an high probability incidence of of visual and/or downstream audio packets having impairments been detected by being observed the gateway 69 by the IPTV as corrupted. customer. The “FE_ES” (far The “FE_CV/ end errored FE_ES” seconds) parameter is an parameter is an example of a example of a compound parameter parameter indicative of an indicative of a incidence of rate at which fixed-duration requests for intervals (e.g., 1- retransmission second intervals) are issued by the containing at IPTV application least one running on the downstream STB 70. packet detected by the gateway 69 as corrupted. FE_CV/FE_SESM AccessCare Far End Code This ratio is an A high CV-to- 15 min Violations divided indicator of how SES ratio in the by Far End the Code downstream Severely Errored Violations in the direction Seconds downstream suggests that The “FE_CV” (far direction are CVs are also end code distributed while likely occurring violations) the DSL outside of the parameter is an connection is intervals when example of a reporting severely the DSL parameter errored seconds connection is indicative of an during the 15-min experiencing incidence of interval. SES condition, downstream and there is a packets having high probability been detected by that IPTV the gateway 69 customer will as corrupted. experience visual The “FE_SESM” and audio (far end severely impairments errored seconds) during the 15-min parameter is an interval. example of a The “FE_CV/ parameter FE_SESM” indicative of an parameter is an incidence of example of a severely errored compound intervals, where parameter a severely indicative of an errored interval is incidence of a fixed-duration downstream interval (e.g., a 1- packets having second interval) been corrupted containing more outside the than a threshold severely errored number of intervals. downstream packets that are detected by the gateway 69 as corrupted. FE_CV/HOLES D-Server| Far End Code Code Violations in A high CV-to- AC Violations divided the downstream Holes in the 15 min by Number of direction may lead downstream Holes to packet loss (i.e. direction The “FE_CV” (far holes) at the set- suggests that a end code top box during the higher probability violations) 15-min interval. of holes greater parameter is an than 150 ms, example of a which are not parameter being requested indicative of an for incidence of retransmission. downstream This will result in packets having visual and audio been detected by impairments. the gateway 69 The “FE_CV/ as corrupted. HOLES” The “HOLES” parameter is an (number of example of a holes) parameter compound is an example of parameter a parameter indicative of a indicative of an likelihood that a incidence of gaps gap detected by between the IPTV downstream application packets received running on the by the IPTV STB 70 will have application a size exceeding running on the a threshold size. STB 70 from the gateway 69. FE_CV/PKTS_REQ D-Server| Far End Code The CV-to-Packet A high CV-to- AC Violations divided Requested ratio in Packet 15 min by Number of the downstream Requested ratio Packets direction is an in the Requested indication of the downstream Code Violations impact of code direction would in the violations on IPTV suggest that non- downstream packets (vs. IPTV packets direction may Internet packets) may also be lead to packet during the 15-min impacted. loss at the set- interval. The “FE_CV/ top box. PKTS_REQ” The “FE_CV” (far parameter is an end code example of a violations) compound parameter is an parameter example of a indicative of a parameter degree to which indicative of an packets related incidence of to at least one downstream other application packets having running in the been detected by end-user the gateway 69 equipment 30_(x) as corrupted. (e.g., the Internet The browser “PKTS_REQ” application (number of running on the packets computer 67) are requested) corrupted. parameter is an example of a parameter indicative of an incidence of gaps between downstream packets received by the IPTV application running on the STB 70 from the gateway 69. FE_CV_SUB_HOLES D-Server| Far End Code Code Violations in A high value AC Violations minus the downstream suggests that a 15 min Number of Holes direction may lead higher probability The “FE_CV” (far to packet loss (i.e. of holes greater end code holes) at the set- than 150 ms, violations) top box during the which are not parameter is an 15-min interval. being requested example of a for parameter retransmission. indicative of an This will result in incidence of visual and audio downstream impairments. packets having The been detected by “FE_CV_SUB_HOLES” the gateway 69 parameter is an as corrupted. example of a The “HOLES” compound (number of parameter holes) parameter indicative of a is an example of likelihood that a a parameter gap detected by indicative of an the IPTV incidence of gaps application between running on the downstream STB 70 will have packets received a size exceeding by the IPTV a threshold size. application running on the STB 70 from the gateway 69. FE_CV_SUB_PKTS_REQ D-Server| Far End Code Code Violations in A high value AC Violations minus the downstream suggests that a 15 min. Packets direction may lead higher probability Requested to packet loss (i.e. of holes greater The “FE_CV” (far holes) at the set- than 150 ms, end code top box during the which are not violations) 15-min interval. being requested parameter is an for example of a retransmission. parameter This will result in indicative of an visual and audio incidence of impairments. downstream The packets having “FE_CV_SUB_PKTS_REQ” been detected by parameter is an the gateway 69 example of a as corrupted. compound The parameter “PKTS_REQ” indicative of a (packets likelihood that a requested) gap detected by parameter is an the IPTV example of a application parameter running on the indicative of an STB 70 will have incidence of gaps a size exceeding between a threshold size. downstream packets received by the IPTV application running on the STB 70 from the gateway 69. FE_ES AccessCare Far End - Far End Errored The presence of 15 min Errored Seconds Seconds refers to error seconds is This is a the count of 1- an indication of measure of second intervals problems with errors in the DSL during which: one the DSL line for the or more CRC connection which downstream anomalies, or may impact the direction (i.e. defects such as transmission, from DSLAM to severely errored resulting in re- residential frame (SEF), loss transmission of gateway), and of signal (LOS), packets or will affect both loss of power packet loss. IPTV and (LPR) are Uncorrected Internet packets detected at the errors in IPTV being transmitted Residential packets in the at the time of Gateway (i.e. downstream error condition. downstream). direction may lead to video defects such as pixilation, screen freeze, etc. or audio defects such as clipping. FE_HBER AccessCare Far End - High A high bit error A DSL 15 min Bit Error Rate rate is an connection with This parameter indication of the high bit error rate indicates that a presence of in the high bit error rate disturbers such as downstream is detected by high noise level in direction will the Residential the DSL likely have a high Gateway (i.e. connection, as count of code downstream). detected by the violations, Residential errored seconds, Gateway. etc., which will likely result in visual and audio impairments. FE_SESM AccessCare Far End - This is a count of A DSL 15 min Severely Errored 1-second intervals connection with Second during which there high count of This measures are: 18 or more severely errored the number of 1- CRC anomalies, seconds in the sec intervals in or one or more downstream which the DSL LOS (loss of direction will connection has signal), SEF likely result in experienced (severe errored visual artefacts severe error frame) or LPR such as pixilation conditions in the (loss of power) or screen freeze downstream defects are and/or audio direction. detected at the impairments residential such as clipping. gateway (i.e. downstream). FE_SFR AccessCare Far End - This is a count of includes both 15 min Superframe the number of IPTV and Received superframes (or Internet traffic This is a blocks) received measure of the by the residential amount of traffic gateway from the being sent from DSLAM during the the DSLAM to 15-min interval the residential (i.e. downstream) gateway (i.e. downstream) FE_SFT AccessCare Far End - This is a count of includes both 15 min Superframe the number of IPTV and Transmitted superframes (or Internet traffic This is a blocks) sent from measure of the the residential amount of traffic gateway to the being sent from DSLAM during the the residential 15-min interval gateway to the (i.e. upstream). DSLAM (i.e. upstream) FE_UAS AccessCare Far End - A DSL line A DSL 15 min Unavailable becomes connection with Second unavailable at the unavailable An unavailable onset of 10 second(s) in the second is a count contiguous SES downstream of 1-second (severely errored direction will intervals for seconds). likely result in which the DSL This parameter loss of video line is shows the count signal (i.e. IPTV unavailable at of 1-sec intervals service outage) the DSLAM. during which the during the 15-min DSL line is interval. unavailable at the Residential Gateway. ISW AccessCare| This is the cont Packets dropped Reflects in the CMS| of packets by the home user experience Snapshot| dropped by the wiring. During a through pixilation 15 min inside wiring of a 15 minute period if and freezing of home there are no the screen Calculated as packets being The “ISW” follows: reported dropped parameter is an Total_Packets_Expired - by the local loop example of a FE_CV - and no packets compound disc_sent - disc_rcvd being dropped by parameter The the modem yet the indicative of a “Total_Packets_Expired” STB report faultiness of a parameter is an packets being connection example of a dropped through between the parameter the D-Server gateway 69 and indicative of an packets requested the STB 70. incidence of and packets downstream expired, then the packets not home wiring is reaching the causing the issue. IPTV application This measure can running on the isolate precisely STB 70 in time which STB is a for a content of problem and point the packets to be a technician to the delivered to the right device user 65 of the quickly—therefore IPTV application reducing the time running on the to resolve the STB 70. trouble For instance, in some cases, an example of the “Total_Packets_Expired” parameter may be a number of downstream packets that were expected by the IPTV application running on the STB 70 within a fixed-duration interval and were either not received before expiration of the fixed-duration interval or were received in corrupted form. The “FE_CV” parameter is an example of a parameter indicative of an incidence of downstream packets having been detected by the gateway 69 as corrupted. The “disc_sent” parameter is an example of a parameter indicative of an incidence of downstream packets intended for the IPTV application running on the STB 70 having been discarded by the gateway 69 without having been sent to the IPTV application running on the STB 70. The “disc_rcvd” parameter is an example of a parameter indicative of an incidence of upstream packets intended for the access network 26 having been discarded by the gateway 69 without having been sent to the access network 26. Link Resync CMS Link Retrain is a Link retrain can Link retrain will Daily re-sync of the occur when a DSL likely result in DSL connection. connection temporary IPTV encounters service outage severely errored frame (SEF) defects, high signal-to-noise (SNR) ratio, loss of frames (LOF) or loss of signal (LOS), etc. MAX_HOLE_SIZE D-Server Maximum Hole This parameter The closer this 15 min Size is the the captures the value is to largest hole largest hole (i.e. 150 ms, the encountered packet discard or higher the (measured in ms) loss), up to probability for by set top box 150 ms, holes greater over the 15-min encountered than 150 ms and interval during a 15-min the more likely interval. visual and/or audio impairments will be experienced by the IPTV customer. NE_CB AccessCare Near End - This is a count of Corrected Blocks 15 min Corrected Block the number of should not have This is a blocks at the any direct impact measure of the DSLAM (i.e. on IPTV number of upstream) which customer packets with have been experience. errors which corrected using have been FEC (forward corrected in the error correction) upstream during the 15-min direction. interval. NE_CV AccessCare Near End - Code Code violation is Depending on 15 min Violation defined as a count the severity, the This is a of the CRC presence of code measure of anomalies violations leads errors conditions occurring during to errored of the DSL the accumulation seconds or connection in the period (15-min). severely errored upstream Near End Code seconds. direction. Violation refers to High CVs in the CRC anomalies upstream received by the direction may DSLAM (i.e. lead to slow upstream) response in channel change time or some PVR commands. NE_CV/HOLES D-Server| Near End Code Code violations in A value of 0 AC Violations divided the upstream indicates that 15 min by Number of direction may requests for all Holes impact the ability holes less than The “NE_CV” of the set-top box 150 ms should be (near end code to request re- received by the violations) transmission of D-Server. parameter is an packets from the A high CV-to- example of a D-Server during Holes ratio parameter the 15-min indicates a indicative of an interval. higher probability incidence of of requests for upstream retransmission packets sent not being from the gateway received by the 69 to the access D-Server. network 26 The “NE_CV/ having been HOLES” detected by the parameter is an access network example of a 26 as corrupted. compound The “HOLES” parameter (number of indicative of a holes) parameter likelihood that a is an example of request for a parameter retransmission indicative of an issued by the incidence of gaps IPTV application between running on the downstream STB 70 will not packets received reach the D- by the IPTV server of the application content running on the distribution entity STB 70 from the 48. gateway 69. NE_CV/NE_ES AccessCare Near End Code This ratio is an A high CV-to-ES 15 min Violations divided indicator of how ratio in the by Near End the Code upstream Errored Seconds Violations in the direction will The “NE_CV” upstream direction likely result in (near end code are distributed slow response in violations) during the 15-min channel change parameter is an interval. time or some example of a PVR commands parameter during the indicative of an periods when the incidence of DSL line is upstream reporting error packets sent seconds. from the gateway The “NE_CV/ 69 to the access NE_ES” network 26 parameter is an having been example of a detected by the compound access network parameter 26 as corrupted. indicative of a The “NE_ES” time taken to (near end errored service an seconds) interactive parameter is an command (e.g., a example of a channel change parameter or VOD indicative of an command) incidence of provided by the fixed-duration user 65 of the intervals (e.g., 1- IPTV application second intervals) running on the containing at STB 70. least one upstream packet sent from the gateway 69 that is detected by the access network 26 as corrupted. NE_CV/NE_SESM AccessCare Near End Code This ratio is an A high CV-to- 15 min Violations divided indicator of how SES ratio in the by Near End the Code upstream Severely Errored Violations in the direction Seconds upstream direction suggests that The “NE_CV” are distributed CVs are also (near end code while the DSL likely occurring violations) connection is outside of the parameter is an reporting severely intervals when Example of a errored seconds the DSL parameter during the 15-min connection is indicative of an interval. experiencing incidence of SES condition, Upstream and there is a packets sent high probability from the gateway that slow 69 to the access response time in network 26 channel change having been or PVR Detected by the commands will access network be experienced 26 as corrupted. during the 15-min The “NE_SESM” interval. (near end The “NE_CV/ severely errored NE_SESM” seconds) parameter is an parameter is an example of a example of a compound parameter parameter indicative of an indicative of an incidence of incidence of severely errored upstream intervals, where packets having a severely been corrupted errored interval is outside the a fixed-duration severely errored interval (e.g., a 1- intervals. second interval) containing more than a threshold number of upstream packets sent from the gateway 69 that are detected by the access network 26 as corrupted. NE_CV/PKTS_REQ D-Server| Near End Code Code violations in A high CV-to- AC Violations divided the upstream Packet 15 min by Packets direction may Requested ratio Requested impact the ability in the upstream The “NE_CV” of the set-top box direction will (near end code to request re- likely lead to violations) transmission of unfilled holes, parameter is an packets from the resulting in visual example of a D-Server during and/or audio parameter the 15-min impairments. indicative of an interval. The “NE_CV/ incidence of PKTS_REQ” upstream parameter is an packets sent example of a from the gateway compound 69 to the access parameter network 26 indicative of a having been likelihood that a detected by the request for access network retransmission 26 as corrupted. issued by the The IPTV application “PKTS_REQ” running on the (packets STB 70 will not requested) reach the D- parameter is an server of the example of a content parameter distribution entity indicative of an 48. incidence of gaps between downstream packets received by the IPTV application running on the STB 70 from the gateway 69. NE_CV_SUB_HOLES D-Server| Near End Code Code violations in A negative value AC Violations minus the upstream indicates that 15 min Number of Holes direction may most/all packet The “NE_CV” impact the ability retransmission (near end code of the set-top box requests should violations) to request re- be received by parameter is an transmission of the D-server. example of a packets from the The parameter D-Server during “NE_CV_SUB_HOLES” indicative of an the 15-min parameter is an incidence of interval. example of a upstream compound packets sent parameter from the gateway indicative of a 69 to the access likelihood that a network 26 request for having been retransmission detected by the issued by the access network IPTV application 26 as corrupted. running on the The “HOLES” STB 70 will not (number of reach the D- holes) parameter server of the is an example of content a parameter distribution entity indicative of an 48. incidence of gaps between downstream packets received by the IPTV application running on the STB 70 from the gateway 69. NE_CV_SUB_PKTS_REQ D-Server| Near End Code Code violations in A negative value AC Violations minus the upstream indicates that 15 min Number of direction may most/all packet Packets impact the ability retransmission Requested of the set-top box requests should The “NE_CV” to request re- be received by (near end code transmission of the D-server. violations) packets from the The parameter is an D-Serve during “NE_CV_SUB_PKTS_REQ” example of a the 15-min parameter is an parameter interval. example of a indicative of an compound incidence of parameter upstream indicative of a packets sent likelihood that a from the gateway request for 69 to the access retransmission network 26 issued by the having been IPTV application detected by the running on the access network STB 70 will not 26 as corrupted. reach the D- The server of the “PKTS_REQ” content (packets distribution entity requested) 48. parameter is an example of a parameter indicative of an incidence of gaps between downstream packets received by the IPTV application running on the STB 70 from the gateway 69. NE_ES AccessCare Near End - Near End Errored The presence of 15 min Errored Seconds Seconds refers to error seconds is This is a the count of 1- an indication of measure of second intervals problems with errors in the DSL during which one the DSL line for the or more: CRC connection which upstream anomalies, or may impact the direction (i.e. defects such as transmission, from residential severely errored resulting in re- gateway to frame (SEF), loss transmission of DSLAM), and will of signal (LOS), packets or affect both IPTV loss of power packet loss. and Internet (LPR) are Uncorrected packets being detected at the errors in the transmitted at the DSLAM (i.e. upstream time of error upstream) direction may condition. lead to slow response in channel change time or some PVR commands. NE_HBER AccessCare Near End - High A high bit error A DSL 15 min Bit Error Rate rate is an connection with This parameter indication of the high bit error rate indicates that a presence of in the upstream high bit error rate disturbers such as direction will is detected by high noise level in likely lead to slow the DSLAM (i.e. the DSL response in upstream). connection, as channel change detected by the time and some DSLAM. PVR commands. NE_LIA AccessCare Near End - Line The NE_LIA IPTV service 15 min Initiation Attempt counter is only outage will occur This is a count of registered by the during DSL line the number of DSLAM after a re-sync. DSL line attempt line re-sync has to re-syncs. successfully been completed re- sync has been completed during the 15-min time interval. NE_LOLS AccessCare Near End - Loss Loss of Link may A loss of link for 15 min of Link Seconds occur due to the DSL This is a count of severely errored connection will 1-second frame (SEF) result in IPTV intervals during defects, loss of service outage. which there is a signal (LOS), loss loss of link for the of power (LPR), DSL connection, etc. as measured at the DSLAM over a 15-min interval. NE_SESM AccessCare Near End - This is a count of A DSL 15 min Severely Errored 1-second intervals connection with Second during which there high count of This measures are: 18 or more severely errored the number of 1- CRC anomalies, seconds in the sec intervals in or one or more upstream which the DSL LOS (loss of direction will connection has signal), SEF likely result in experienced (severe errored slow response in severe error frame) or LPR channel change conditions in the (loss of power) time and/or some upstream defects are PVR commands. direction. detected at the DSLAM (i.e. upstream). NE_SFR AccessCare Near End - This is a count of includes both 15 min Superframe the number of IPTV and Received superframes (or Internet traffic This is a blocks) received measure of the by the DSLAM amount of traffic from the being sent from residential the residential gateway to the gateway to the residential DSLAM (i.e. gateway during upstream) the 15-min interval (i.e. upstream) NE_SFT AccessCare Near End - This is a count of includes both 15 min Superframe the number of IPTV and Transmitted superframes (or Internet traffic This is a blocks) sent from measure of the the DSLAM to the amount of traffic residential being sent from gateway during the DSLAM to the 15-min interval the residential (i.e. downstream). gateway (i.e. downstream) NE_UAS AccessCare Near End - By definition, a A DSL 15 min Unavailable DSL line becomes connection with Second unavailable at the unavailable onset of 10 second(s) in the contiguous SES upstream (severely errored direction will lead seconds). to difficulty with This parameter channel change shows the count or some PVR of 1-sec intervals commands during which the during the 15-min DSL line is interval. unavailable at the DSLAM. PACKETS_REQUESTED D-Server Number of This is a count of A high value of 15 min Packets the number of number of Requested to be packets requested packets retransmitted to by the set-top box requested for the set-top box to be re- retransmission from the D- transmitted (for indicates a Server holes smaller than higher probability 150 ms) from the of visual or audio D-Server during impairment. the 15-min interval. PACKETS_SERVICED D-Server Number of This is a count of A high value of 15 min Packets the number of number of requested to be packets being re- packets retransmitted to transmitted from the set-top box the D-Server to a which have been set-top box during fulfilled by the D- the 15-min Sever interval. PKT_SERV_SUB_PKT_REQ D-Server Packets Serviced This parameter A value of 0 15 min minus Packets provides an indicates all Requested indication of how requests for The successful the D- retransmission “PKT_SERV” Server is in (for holes less (packets fulfilling the than 150 ms) serviced) request for packet have been parameter is an retransmission by fulfilled by the D- example of a the set-top box. Server. parameter A negative value indicative of an indicates that not incidence of all requests for missing retransmission downstream have been packets having fulfilled, which been would result in retransmitted by visual or audio the D-server of impairments. the content The distribution entity “PKT_SERV_SUB_PKT_REQ” 48. parameter is an The “PKT_REQ” example of a (packets compound requested) parameter parameter is an indicative of a example of a success rate of parameter the D-server of indicative of an the content incidence of distribution entity missing 48 in handling downstream requests for packets for which retransmission a request for issued by the retransmission IPTV application has been issued running on the by the IPTV STB 70. application running on the STB 70. REBOOT CMS|5530| Number of IPTV service AccessCare Reboots outage occurs This is a count of when the the number of residential times the gateway reboots. residential gateway reboots during the 15-min time interval. RETRY_NUMBER D-Server Number of Holes This parameter A high value of 15 min encountered at counts the number retry indicates a the set-top box of holes smaller higher probability than 150 ms of visual or audio encountered by impairment. the set-top box during the 15-min interval. TOTAL_HOLE_PKTS Snapshot Total Hole This is the total This provides an Packets is the number of packets indication of the total number of for all large holes number of packets for all and unfilled holes packets required holes for all live TV for encountered by channels. retransmission. the set-top box For holes greater than 150 ms, there will be no request for re- transmission, and visual/audio impairments will be experienced by IPTV customers. TOTAL_PKTS_EXPIRED Snapshot Total Packets This is the total A positive value Expired is the number of expired indicates that total number of packets (i.e. out- visual and/or packets which of-order packets audio took too long to or have taken too impairments will arrive at the set- long to arrive) for be experienced top box all large holes and by the IPTV unfilled holes for customer. all live TV channels. TOTAL_PKTS_RCVD Snapshot Total Packets This is a count of Received is the the total number total number of of packets packets received received for all live by the set-top TV channels by box. the set-top box. TOTAL_PKTS_SENT CMS Total Number of A measure of the Daily Packets Sent by amount of traffic Residential being sent by the Gateway residential gateway to devices connected to the home network.

In this embodiment, the IPTV service parameters may be categorized in different ways.

For example, in this embodiment, one way in which the IPTV service parameters may be categorized is based on where they are measured (e.g., in the subscriber premises 28 _(x), in the access network 26, etc.). In particular, in this embodiment, some of the IPTV service parameters which are used by the service monitoring entity 45 to assess the QoE of the subscribers are measured in the access network 26. More specifically, in this embodiment, these parameters may be measured by the monitoring entity 58 of the access network 26. This is particularly useful as it can provide insight that could not be otherwise achieved when considering IPTV service parameters only measured by the end-user equipment 30 _(x) at the subscriber premises 28 _(x). For example, in this case, the “NE_CV” parameter, which refers to near end code violations reflecting a measure of errors conditions of the DSL connection in the upstream direction (i.e., towards the DSLAM 64), is based on measurements performed by the monitoring entity 58 of the access network 26.

As another example, in this embodiment, another way in which the IPTV service parameters may be categorized is by categorizing them as “independent” IPTV service parameters and “compound” IPTV service parameters.

An independent IPTV service parameter can be viewed as a metric which is directly measured and does not depend on another IPTV service parameter. For instance, one example of an independent IPTV service parameter that is listed in Table 1 is the “DISCARD_PKTS_SENT” parameter, which refers to the number of packets intended to be sent by the residential gateway 69 to the STB 70 but that have been discarded by the residential gateway 69 instead of being sent to the STB 70. Another example of an independent IPTV service parameter that is listed in Table 1 is the “PACKETS_REQUESTED” parameter, which refers to the number of packets requested to be retransmitted in requests for retransmission issued by the STB 70.

A “compound” IPTV service parameter can be viewed as a metric which is a function of a plurality of IPTV service parameters. A compound IPTV service parameter may provide insight that cannot be obtained when considering individually the IPTV service parameters on which it depends. For instance, one example of a compound IPTV service parameter that is listed in Table 1 is the “DISC_SENT/REQ” parameter, which refers to a ratio of the “DISCARD_PKTS_SENT” parameter (i.e., the number of packets intended to be sent by the residential gateway 69 to the STB 70 but that have been discarded by the residential gateway 69) and the “PACKETS_REQUESTED” parameter (i.e., the number of packets requested to be retransmitted in requests for retransmission issued by the STB 70). A ratio of 1:1 would strongly suggest that the holes encountered at the STB 70 are likely caused by the packets being discarded before being sent by the residential gateway 69. A high ratio may be an indication that the holes caused by the packets being discarded are larger than 150 ms (i.e., they are too large such that no request for retransmission is issued by the STB 70).

The function defining a given compound IPTV service parameter may take on various forms. In the examples of compound IPTV service parameters listed in Table 1, the function defining each compound parameter is purely arithmetic. More particularly, in these examples, the function defining a given compound IPTV service parameter is a division of one parameter by another or a subtraction of one parameter from another. Thus, in these examples, a given compound IPTV service parameter may be determined by determining an arithmetic difference between, or a quotient of, a first operand that comprises a first IPTV service parameter on which the given IPTV service compound parameter depends and a second operand that comprises a second IPTV service parameter on which the given IPTV service compound parameter depends, as the case may be. Instead of a quotient, a logarithmic difference may be equivalently used in some cases. The function defining a given compound IPTV service parameter may be more complex in other examples.

In this embodiment, a given compound IPTV service parameter may be a function of two or more other IPTV service parameters which gives an indication of a likelihood of a situation affecting QoE of the subscriber, possibly causing a service impairment for the subscriber (i.e., video and/or audio impairment, such as pixelation, screen freezing, etc.).

For example, when packets are dropped and the STB 70 encounters, the STB 70 issues requests for retransmission of the dropped packets for holes no greater than 150 ms. Based only on the number of retransmission requests received at a D-server of the content distribution entity 48 (the IPTV service parameter “RETRY_NUMBER”), one does not know whether some requests for retransmission sent to the D-Server get dropped before reaching the D-Server or whether packets retransmitted by the D-server get dropped before reaching the STB 70. However, a higher value of the IPTV service parameter “DISC_RCVD/HOLES” can indicate a higher likelihood of requests for retransmission from the STB 70 failing to reach the D-Server and resulting in visual and/or audio impairment for the subscriber.

As another example, requests for packet retransmission received by a D-server of the content distribution entity 48 indicate that packets are dropped before reaching the STB 70. Based on the number of retransmission requests alone, one cannot know whether the dropped packets are causing a service impairment for the subscriber. However, a higher value of the IPTV service parameter “DISC_SENT/REQ” can indicate that the holes caused by the packets being discarded are larger than 150 ms (i.e. they are too large so that no request for retransmission is issued), thus causing video and/or audio impairment for the subscriber.

Other examples of IPTV service parameters which give indications of likelihood of situations affecting QoE of the subscribers are presented in Table 1. Yet other examples may be envisaged in other embodiments.

The service monitoring entity 45 of the SHE 20 collects and processes the values of the IPTV service parameters to provide insight into the QoE of each of the subscribers. More particularly, based on the values of the IPTV service parameters for the subscriber at the subscriber premises 28 _(x), the service monitoring entity 45 derives information indicative of the QoE of the subscriber. This information, which will be referred to as “QoE information”, can be derived in various ways.

For example, in this embodiment, the QoE information for the subscriber comprises a plurality of levels of QoE of the subscriber for different periods of time (e.g., a fraction of an hour, an hour, a day, a week, a month) which provide insight into the QoE of the subscriber at different degrees of temporal resolution or granularity. These levels of QoE are attributed by the service monitoring entity 45 based on the values of the IPTV service parameters. Since they can be viewed as basically rating the QoE of the subscriber, the levels of QoE of the subscriber that are determined by the service monitoring entity 45 can be viewed as “ratings of QoE”. More particularly, in this embodiment, the QoE information comprises a QoE rating for every interval of fifteen minutes (hereinafter referred to as a “15-min QoE rating”), a QoE rating for every day (hereinafter referred to as a “daily QoE rating”), a QoE rating for every week (hereinafter referred to as a “weekly QoE rating”), and a QoE rating for every month (hereinafter referred to as a “monthly QoE rating”).

The QoE ratings can be derived in many different ways based on the values of the IPTV service parameters for the subscriber. An example of how the QoE ratings for the subscriber may be derived in this embodiment will now be discussed, with additional reference to FIGS. 5 and 6.

a) 15-min QoE Rating

The values of the IPTV service parameters which are measured every 15 minutes are rated to obtain ratings for these parameters. These ratings, which will be referred to as “parameter ratings”, are taken from a set of potential parameter ratings which constitute a parameter rating scale. The parameter rating scale can take on various forms. For example, as shown in Table 2, in this embodiment, the parameter rating scale includes three potential parameter ratings, namely “green”, “yellow”, and “red”. The value of a given IPTV service parameter for a particular 15-min interval may be attributed: the “green” parameter rating when it is considered to be in a normal or standard range for this parameter; the “yellow” parameter rating when it is considered to be outside the normal or standard range for this particular parameter by a degree which is unlikely to be indicative of a problem affecting the subscriber's QoE; and the “red” parameter rating when it is considered to be so outside the normal or standard range for this particular parameter that it likely indicates a problem affecting the subscriber's QoE.

In this embodiment, a parameter rating is attributed to the value of a given IPTV service parameter for a particular 15-min interval by comparing this value to one or more thresholds. Such thresholds may be determined by the service provider (e.g., based on conditions which clearly demonstrate impairments of the IPTV service to the subscriber). Examples of such thresholds are provided in Table 2.

For example, in this case, the value of the “DISCARD_PKTS_SENT” parameter for a particular 15-min interval is compared to a first threshold of 200 discarded packets and a second threshold of 9000 discarded packets. If the value of the “DISCARD_PKTS_SENT” parameter is less than or equal to 200, it is attributed the “green” parameter rating. If the value of the “DISCARD_PKTS_SENT” parameter is greater than or equal to 9000, it is attributed the “red” parameter rating. If the value of the “DISCARD_PKTS_SENT” parameter is between 200 and 9000, it is attributed the “yellow” parameter rating.

The 15-min QoE rating for the subscriber for a particular 15-min interval is derived on a basis of the parameter ratings of the values of the IPTV service parameters for the particular 15-min interval. Specifically, in this example, the 15-min QoE rating for the subscriber for the particular 15-min interval is taken from a set of potential 15-min QoE ratings which forms a 15-min QoE rating scale or range. For example, in this embodiment, the 15-min QoE rating scale or range includes four potential 15-min QoE ratings, namely “green”, “yellow”, “red”, and “blue” (which are represented by different cross-hatching patterns in FIGS. 5 and 6). A “green” 15-min QoE rating may be attributed when the subscriber's QoE is deemed to be normal or standard for the particular 15-min interval. A “yellow” 15-min QoE rating may be attributed when the subscriber's QoE is deemed to be affected by a relatively minor issue during the particular 15-min interval. A “red” 15-min QoE rating may be attributed when the subscriber's QoE is deemed to be affected by a relatively major issue during the particular 15-min interval. A “blue” 15-min QoE rating may be attributed when the subscriber's QoE is deemed to be affected by an issue during a primetime viewing period, which is determined by the service provider (e.g., 8:00 pm to 11:00 pm Eastern and Pacific and 7:00 pm to 10:00 pm Central and Mountain from Monday to Saturday, and 7:00 pm to 11:00 pm Eastern and Pacific and 6:00 pm to 10:00 pm Central and Mountain on Sunday).

The 15-min QoE rating for the subscriber for the particular 15-min interval is determined based on criteria defined in terms of the parameter ratings of the values of the IPTV service parameters for the particular 15-min interval. For instance, in this example:

-   -   If every one of the parameter ratings of the values of the IPTV         service parameters for the particular 15-min interval is the         “green” parameter rating, then the 15-min QoE rating for the         particular 15-min interval is the “green” QoE rating.     -   If any of the parameter ratings of the values of the IPTV         service parameters for the particular 15-min interval is the         “red” parameter rating, then the 15-min QoE rating for the         particular 15-min interval is the “red” QoE rating.     -   If any of the parameter ratings of the values of the IPTV         service parameters for the particular 15-min interval is the         “yellow” parameter rating but none of these parameter ratings is         the “red” parameter rating, then the 15-min QoE rating for the         particular 15-min interval may be the “yellow” QoE rating or the         “red” QoE rating, depending on the number of “yellow” parameter         ratings for the particular 15-min interval. For instance, if the         number of “yellow” parameter ratings for the particular 15-min         interval is below a threshold (e.g., 4 or any other number), the         15-min QoE rating for the particular 15-min interval may be the         “yellow” QoE rating; otherwise, if the number of “yellow”         parameter ratings for the particular 15-min interval is at or         above the threshold, the 15-min QoE rating for the particular         15-min interval may be the “red” QoE rating.     -   If the particular 15-min interval falls within a primetime         viewing period determined by the service provider and any of the         parameter ratings of the values of the IPTV service parameters         for the particular 15-min interval is the “yellow” or “red”         parameter rating, then the 15-min QoE rating for the particular         15-min interval is the “blue” QoE rating.

Various other criteria may be applied in other embodiments to attribute the 15-min QoE rating for the particular 15-min interval.

This approach is applied to each of the ninety-six 15-min intervals in a day in order to obtain ninety-six 15-min QoE ratings for the subscriber for that day.

The 15-min QoE ratings for the subscriber are examples of intraday ratings for periods of time shorter than one day that can be attributed. In other embodiments, intraday ratings for longer or shorter periods of time can be used (e.g., 5-min QoE ratings, 30-min QoE ratings, 1-hour QoE ratings, 3-hour QoE ratings, etc.).

TABLE 2 Thresholds Measure Red Yellow Green CRASH_COUNT  1 Only Red or Green 0 DISC_RCVD/HOLES 200+ 101-199 <=100 DISC_RCVD/REQ 200+ 101-199 <=100 DISC_SENT/HOLES 200+ 101-199 <=100 DISC_SENT/REQ 200+ 101-199 <=100 DISCARD_PKTS_RCVD 9000+   201-8999 <=200 DISCARD_PKTS_SENT 9000+   201-8999 <=200 ERRORS_RCVD 150,000+    Not defined but will <=200 use a blended metric to determine status ERRORS_SENT 150,000+    Not defined but will <=200 use a blended metric to determine status FE_CB No Threshold No Threshold No Threshold FE_CV 9,000+   Not defined but will <=200 use a blended metric to determine status FE_CV/FE_ES 100+ 11-99 <=10 FE_CV/FE_SESM 100+ 11-99 <=10 FE_CV/HOLES 100+ 11-99 <=10 FE_CV/PKTS_REQ 100+ 11-99 <=10 FE_CV_SUB_HOLES 1000+   11-999 <=10 FE_CV_SUB_PKTS_REQ 1000+   11-999 <=10 FE_ES No Threshold No Threshold No Threshold Not an indicator on Not an indicator on Not an indicator on it's own but used it's own but used it's own but used as a combined measure as a combined measure as a combined measure with others with others with others FE_HBER  5+ 1-4 0 FE_SESM  5+ 1-4 0 FE_SFR No Threshold No Threshold No Threshold FE_SFT No Threshold No Threshold No Threshold FE_UAS  5+ 1-4 0 ISW  40+ 11-39 <=10 Link Resync  2 1 0 MAX_HOLE_SIZE No Threshold No Threshold No Threshold NE_CB No Threshold No Threshold No Threshold NE_CV 9,000+   Not defined but will <=200 use a blended metric to determine status NE_CV/HOLES 100+ 11′99 <=10 NE_CV/NE_ES 100+ 11′99 <=10 NE_CV/NE_SESM 100+ 11′99 <=10 NE_CV/PKTS_REQ 100+ 11′99 <=10 NE_CV_SUB_HOLES 1000+   11-999 <=10 NE_CV_SUB_PKTS_REQ 1,000+    11-999 <=10 NE_ES No Threshold No Threshold No Threshold Not an indicator on Not an indicator on Not an indicator on it's own but used it's own but used it's own but used as a combined measure as a combined measure as a combined measure with others with others with others NE_HBER  5+ 1-4 0 NE_LIA  1 Either Red or Green 0 nothing in between NE_LOLS  5+ 1-4 0 NE_SESM  5+ 1-4 0 NE_SFR No Threshold No Threshold No Threshold NE_SFT No Threshold No Threshold No Threshold NE_UAS  5+ 1-4 0 PACKETS_REQUESTED 4500+  Not defined but will <=70 use a blended metric to determine status PACKETS_SERVICED No Threshold No Threshold No Threshold PKT_SERV_SUB_PKT_REQ <=−5   −4 to 0 0 REBOOT  1 Only Red or Green 0 RETRY_NUMBER 4500+  Not defined but will <=70 use a blended metric to determine status TOTAL_HOLE_PKTS No Threshold No Threshold No Threshold TOTAL_PKTS_EXPIRED  5+ 1-4 0 TOTAL_PKTS_RCVD No Threshold No Threshold No Threshold TOTAL_PKTS_SENT No Threshold No Threshold No Threshold b) Daily QoE Rating

The daily QoE rating for the subscriber for a particular day is determined on a basis of the ninety-six 15-min QoE ratings for the subscriber for that day. Specifically, in this example, the daily QoE rating for the subscriber for the particular day is taken from a set of potential daily QoE ratings which forms a daily QoE rating scale or range. For example, in this embodiment, the daily QoE rating scale includes four potential daily QoE ratings, namely “green”, “yellow”, “red”, and “blue”. A “green” daily QoE rating may be attributed when the subscriber's QoE is deemed to be normal or standard for the particular day. A “yellow” daily QoE rating may be attributed when the subscriber's QoE is deemed to be detrimentally affected by a relatively minor issue on the particular day. A “red” daily QoE rating may be attributed when the subscriber's QoE is deemed to be detrimentally affected by a relatively major issue on the particular day. A “blue” daily QoE rating may be attributed when the subscriber's QoE is deemed to be detrimentally affected by an issue during a primetime viewing period on the particular day.

The daily QoE rating for the subscriber for the particular day is determined based on criteria defined in terms of the ninety-six 15-min QoE ratings for the subscriber for that day. For instance, in this example:

-   -   If the number of “yellow” and “red” 15-min QoE ratings for the         particular day is less than or equal to a first threshold, in         this case five, then the daily QoE rating for the particular day         is the “green” daily QoE rating.     -   If the number of “yellow” and “red” 15-min QoE ratings for the         particular day is greater than the first threshold but less than         or equal to a second threshold, in this case twenty, then the         daily QoE rating for the particular day is the “yellow” daily         QoE rating.     -   If the number of “yellow” and “red” 15-min QoE ratings for the         particular day is greater than the second threshold, then the         daily QoE rating for the particular day is the “red” daily QoE         rating.     -   If the number of “blue” 15-min QoE ratings for the particular         day is greater than or equal to a given threshold, in this case         10, then the daily QoE rating for the particular day is the         “blue” daily QoE rating.

The criteria on which the daily QoE rating for the subscriber for the particular day is determined may also take into account the values of the IPTV service parameters which are measured every day. For instance, the value of a given IPTV service parameter which is measured every day is rated to obtain a parameter rating. As discussed above, and as shown in Table 2, in this embodiment, the “green”, “yellow”, and “red” parameter rating is attributed to the value of the given IPTV service parameter for a particular day by comparing this value to one or more thresholds, which are determined by the service provider. As an example, in this case, the value of the “ERRORS_SENT” parameter for a particular day, which refers to the number of errors in the IPTV packets detected by the residential gateway 69, is compared to a first threshold number of 200 errors and a second threshold of 150000 discarded packets. If the value of the “ERRORS_SENT” parameter is less than or equal to 200, it is attributed the “green” parameter rating. If the value of the “ERRORS_SENT” parameter is greater than or equal to 150000, it is attributed the “red” parameter rating. If the value of the “ERRORS_SENT” parameter is between 200 and 150000, it is attributed the “yellow” parameter rating. In such cases, if any of the parameter ratings of the values of the IPTV service parameters for the particular day is the “red” parameter rating, then the daily QoE rating for the particular day is the “red” daily QoE rating, regardless of what are the 15-min QoE ratings for the particular day.

Various other criteria may be applied in other embodiments to attribute the daily QoE rating for the particular day.

This approach is applied to each of the seven days in a week in order to obtain seven daily QoE ratings for the subscriber for that week.

c) Weekly QoE Rating

The weekly QoE rating for the subscriber for a particular week is obtained on a basis of the seven daily QoE ratings for the subscriber for that week. Specifically, in this example, the weekly QoE rating for the subscriber for the particular week is taken from a set of potential weekly QoE ratings which forms a weekly QoE rating scale or range. For example, in this embodiment, the weekly QoE rating scale includes four potential weekly QoE ratings, namely “green”, “yellow”, “red”, and “blue”. A “green” weekly QoE rating may be attributed when the subscriber's QoE is deemed to be normal or standard for the particular week. A “yellow” weekly QoE rating may be attributed when the subscriber's QoE is deemed to be detrimentally affected by a relatively minor issue on the particular week. A “red” weekly QoE rating may be attributed when the subscriber's QoE is deemed to be detrimentally affected by a relatively major issue on the particular week. A “blue” weekly QoE rating may be attributed when the subscriber's QoE is deemed to be detrimentally affected by an issue during a primetime viewing period during the particular week.

The weekly QoE rating for the subscriber for the particular week is determined based on criteria defined in terms of the seven daily QoE ratings for the subscriber for that week. For instance, in this example:

-   -   If the number of “red” daily QoE ratings for the particular week         is less than or equal to a first threshold, in this case one,         then the weekly QoE rating for the particular week is the         “green” weekly QoE rating.     -   If the number of “red” daily QoE ratings for the particular week         is greater than the first threshold but less than or equal to a         second threshold, in this case three, then the weekly QoE rating         for the particular week is the “yellow” weekly QoE rating.     -   If the number of “red” daily QoE ratings for the particular week         is greater than the second threshold, then the weekly QoE rating         for the particular week is the “red” weekly QoE rating.     -   If the number of “blue” daily QoE ratings for the particular         week is greater than or equal to a given threshold, in this case         3, then the weekly QoE rating for the particular week is the         “blue” weekly QoE rating.

The criteria on which the weekly QoE rating for the subscriber for the particular week is determined may also take into account the parameter ratings of certain IPTV service parameters. For instance, the parameter rating of a given IPTV service parameter may be considered to be of sufficient importance that, if it is “red” parameter rating, the weekly QoE rating for the particular week is the “red” weekly QoE rating, regardless of what are the daily QoE ratings for the particular week. As an example, in this case, if the “REBOOT” parameter, which refers to the number of reboots of the residential gateway 69, was attributed the “red” parameter rating anytime during the particular week, the weekly QoE rating for the particular week is the “red” weekly QoE rating, regardless of what are the daily QoE ratings for the particular week.

Various other criteria may be applied in other embodiments to attribute the weekly QoE rating for the particular week.

d) Monthly QoE Rating

The monthly QoE rating for the subscriber for a particular month is obtained on a basis of the daily QoE ratings for the subscriber for that month, in a manner similar to that discussed above in respect of the weekly QoE ratings.

The QoE information for each of the subscribers, including the QoE ratings for each of the subscribers, is recorded and stored in the database 83 of the service monitoring entity 45. The database 83 is implemented by data storage media, which may store data optically (e.g., an optical disk such as a CD-ROM or a DVD), magnetically (e.g., a hard disk drive, a removable diskette), electrically (e.g., semiconductor memory, floating-gate transistor memory, etc.), and/or in various other ways.

By including the 15-min, daily, weekly, and monthly QoE ratings for the subscribers, the QoE information stored in the database 83 maintains a history of each subscriber's QoE which spans several weeks or months (e.g., a rolling period of six months or more) and which can be analyzed on a 15-min, daily, weekly or monthly basis. This archive can allow the service provider to identify issues or trends with respect to each subscriber's QoE. For example, the historical QoE information can allow the service provider to identify recurring issues or patterns experienced by individual subscribers. In order to optimize data storage efficiency, in some embodiments, the historical QoE information stored in the database 83 may be pruned to retain only items of information pertaining to issues experienced by the subscribers. For instance, only the QoE information reflecting “yellow”, “red” or “blue” QoE ratings may be retained.

The QoE information derived by the service monitoring entity 45 can be used in various ways. Generally, based on the QoE information, the service monitoring entity 45 provides a service assurance capability to enable the service provider to know how each subscriber is doing, know where and when trouble or issues arise, and therefore reduce the time and cost to resolve such trouble or issues.

For example, in this embodiment, a user 86 may use a monitoring tool provided by a user device 87 to gain insight into the QoE of the subscribers based on the QoE information derived by the service monitoring entity 45. For instance, in various cases, the user 86 may be a helpdesk agent or other customer service representative, a technician, a network engineer, an executive or other manager, or some other employee of the service provider. The user device 87 comprises an input portion (e.g., a keyboard, a touchscreen, and/or a mouse or other pointing device), an output portion comprising a display and possibly other output components (e.g., a speaker), and a processing portion to process data allowing the monitoring tool to be used by the user 86. In this embodiment, the user device 87 is a personal computer (e.g., a workstation, a desktop computer, a laptop computer, etc.). In other embodiments, the user device 87 may take on other forms (e.g., a mobile phone, a portable technician terminal, etc.).

The monitoring tool is implemented by a monitoring tool application 85. In this embodiment, the monitoring tool application 85 is executed by the processing entity 59 of the service monitoring entity 45. The monitoring tool comprises a graphical user interface (GUI) implemented on the user device 87. The user device 87 is connected to the service monitoring entity 45 via a communications link 55, which may be a wired or wireless link.

The monitoring tool enables the user 86 to interact with its GUI in order to request and be presented with meaningful representations of the QoE information stored in the database 83. The GUI may provide charts, tables, lists and/or any other graphical representation of selected portions of the QoE information stored in the database 83 that are to be presented to the user 86.

For instance, FIGS. 7 to 11 show examples of manifestations of the GUI on the computer 86 in this embodiment. In FIG. 7, a set of tables presents the daily, weekly, and monthly QoE ratings for the subscribers in terms of proportions of the subscribers which had “green”, “yellow”, “red” and “blue” QoE ratings for particulars days, weeks and months. For instance, the table indicates that, on May 18, 2010, 84.05% of the subscribers had “green” daily QoE ratings, 2.45% of the subscribers had “yellow” daily QoE ratings, 6.86% of the subscribers had “red” daily QoE ratings, and 6.63% of the subscribers had “blue” daily QoE ratings. In FIG. 8, the daily, weekly, and monthly QoE ratings for a given subscriber are presented by a calendar which conveys the daily QoE rating for each particular day, a list which conveys the weekly QoE rating for each particular week, and another list which conveys the monthly QoE rating for each particular month. For instance, the calendar and the lists indicate that the subscriber had “red” daily QoE ratings from Apr. 18 to Apr. 21, 2010, a “green” daily QoE rating on Apr. 22, 2010, and a “yellow” daily QoE rating on Apr. 23, 2010, the subscriber had “red” weekly QoE ratings for the weeks of Apr. 4 and Apr. 11, 2010, and the subscriber had a “red” monthly QoE rating for the month of April 2010. In FIGS. 9 to 11, different performance charts are presented.

Various other charts, tables, lists and/or other graphical representations of selected portions of the QoE information stored in the database 83 may be presented to the user 86 via the GUI of the monitoring tool (e.g., representations of the 15-min QoE ratings for a given subscriber, representations of individual ones of the IPTV service parameters for a given subscriber, etc.).

Based on the QoE information stored in the database 83, the user 86 may be alerted to situations affecting the QoE of subscribers. For example, when a particular IPTV service parameter (e.g., a given compound IPTV service parameters indicative of a likelihood of a situation affecting the QoE of a subscriber) is attributed a “red” parameter rating or a particular period of time (e.g., a 15-min interval, a day, a week, or a month) is attributed a “red” QoE rating, output of the “red” parameter rating or “red” QoE rating on the GUI of the computer 86 provides an alert alerting the user 86 to the fact that a situation is potentially affecting the QoE of the subscriber. Other forms of alerts (e.g., pop-up windows, email messages, etc.) may be issued in other embodiments.

The user 86 can use the monitoring tool provided by the user device 87 in order to assess the quality of the IPTV service provided to the subscribers in general or to specific subscribers, to identify issues in connection with this service, and establish corrective actions to resolve these issues.

For example, in cases in which the user 86 is a helpdesk agent or technician who is handling a subscriber's complaint about the IPTV service being poor, the QoE information accessible via the monitoring tool provided by the user device 87 may help the helpdesk agent or technician diagnose the trouble the subscriber is experiencing and be able to fix it as quickly and efficiently as possible. For instance, FIG. 12 shows how the user 86 can use the monitoring tool via the user device 87 to identify the root cause of a subscriber's issue as likely being a particular STB at the subscriber's premises. In particular, since the QoE information reflects the status of the access network 26, the user 86 can exclude the DSL connection as the root cause of the subscriber's issue.

As another example, in some cases, the user 86 may proactively review the QoE information accessible via the monitoring tool provided by the user device 87 to identify specific subscribers experiencing poor service quality (e.g., subscribers having a “red” weekly QoE rating) and reach out to them to resolve the issues before these subscribers notice the poor service or contact the service provider. For instance, the user 86 may contact a given subscriber identified as experiencing poor service to explain the situation and provide a solution to the problem (e.g., instruct the given subscriber to change a cable between the STB 70 and the residential gateway 69, advise the given subscriber that a technician can stop by to resolve the problem, etc.).

Alternatively or additionally, in some embodiments, the processing entity 59 of the service monitoring entity 45 may proactively analyse the QoE information for the subscribers in order to identify specific subscribers experiencing poor service quality (e.g., subscribers having a “red” weekly QoE rating) and automatically take actions to resolve the issues before these subscribers notice the poor service and contact the service provider. For instance, the service monitoring entity 45 may send a communication (e.g., an email, a voice mail, an internal log communication etc.) to a helpdesk agent or a technician to advise of a given subscriber identified as experiencing poor service to explain the situation and provide a solution to the problem. As another example, the service monitoring entity 45 may send a communication (e.g., an email, a voice mail, etc.) to the given subscriber identified as experiencing poor service to explain the situation and provide a solution to the problem (e.g., advise the given subscriber that a technician can stop by to resolve the problem, etc.).

While in the examples considered above the user 86 is an employee of the service provider, in other examples, the user 86 may be the subscriber, who can use the monitoring tool provided by the user device 87 to access the QoE information pertaining to his/her subscription.

Another way in which the QoE information derived by the service monitoring entity 45 can be used is to assess performance of the network 10. Such assessments can give insight into how well the IPTV service is provisioned by the service provider, isolate chronic issues, serve to develop better provisioning standards/guidelines and training programs for technicians, and/or rationalize added investments in connection with the IPTV service. For example, this may be used to isolate problems by identifying which network components (e.g., in the SHE 20, in the core network 22, in the access network 26 or in the end-user equipment 30 _(x)) are causing these problems. For instance, FIG. 13 shows an example of a more detailed architecture over which the IPTV service may be delivered, with rectangular boxes illustrating potential areas where issues affecting delivery of the IPTV service may be encountered.

Although in embodiments discussed above the service monitoring entity 45 and the QoE information that it derives pertain to an IPTV service, in other embodiments, principles discussed herein may apply to other services that can be provided over the packet-switched network 13. For example, in other embodiments, principles discussed herein may apply to an Internet access service and/or a VoIP service provided over the packet-switched network 13. For instance, in such embodiments, a service monitoring entity similar to the service monitoring entity 45 may derive QoE information for subscribers of the Internet access service and/or the VoIP service on a basis of parameters similar to the IPTV service parameters discussed above (e.g., with different thresholds being used in attributing QoE ratings to the parameter values).

While in embodiments considered above, the end-user equipment 30 ₁-30 _(N) of the subscribers is located at the subscriber premises 28 ₁-28 _(N) and the communication links 63 ₁-63 _(N) of the access network 26 include wired links leading to the end-user equipment 30 ₁-30 _(N), in other embodiments, the end-user equipment 30 ₁-30 _(N) of the subscribers may include mobile wireless devices (e.g., cellular phones) and the communication links 63 ₁-63 _(N) may include wireless links (e.g., cellular links) over which the services are delivered.

Those skilled in the art will appreciate that, in some embodiments, a given component described herein (e.g., the service monitoring entity 45) may comprise one or more pre-programmed hardware or firmware elements (e.g., application specific integrated circuits (ASICs), electrically erasable programmable read-only memories (EEPROMs), etc.) or other related elements to implement at least some functionality of that given component. In other embodiments, a given component described herein (e.g., the service monitoring entity 45) may comprise a processor having access to a memory which stores program instructions for execution by the processor to implement at least some functionality of that given component. The program instructions may be stored on data storage media that is fixed, tangible, and readable directly by the processor. The data storage media may store data optically (e.g., an optical disk such as a CD-ROM or a DVD), magnetically (e.g., a hard disk drive, a removable diskette), electrically (e.g., semiconductor memory, floating-gate transistor memory, etc.), and/or in various other ways. Alternatively, the program instructions may be stored remotely but transmittable to the given component via a modem or other interface device connected to a network over a transmission medium. The transmission medium may be either a tangible medium (e.g., optical or analog communications lines) or a medium implemented using wireless techniques (e.g., microwave, infrared or other wireless transmission schemes).

Although various embodiments of the invention have been described and illustrated, it will be apparent to those skilled in the art that numerous modifications and variations can be made without departing from the scope of the invention, which is defined in the appended claims. 

The invention claimed is:
 1. A method of monitoring performance of a system that comprises a gateway connected to an appliance running a media application, wherein downstream packets are received by the media application from a head-end server through the gateway, the method comprising: determining a first parameter indicative of a number of downstream packets that, within a fixed-duration accumulation period of time, have been detected as corrupted for failing an error check performed thereon at the gateway; determining a second parameter indicative of a count of fixed-duration intervals during the fixed-duration accumulation period of time, containing at least one downstream packet detected as corrupted at the gateway, wherein the fixed-duration intervals is shorter than the fixed-duration accumulation period of time; determining, based on at least the first parameter and the second parameter, a compound parameter, for the fixed-duration accumulation period of time, indicative of a rate at which requests for retransmission are issued by the media application during the fixed-duration accumulation period of time; determining a level of quality of experience (QoE) of a user of the appliance to be within a normal range when the compound parameter for the fixed-duration accumulation period of time is below a first threshold value, the first threshold value being lower than a second threshold value; determining the level of QoE of the user to be outside normal range indicating a minor issue affecting the QoE of the user when the compound parameter for the fixed-duration accumulation period of time is between the first threshold value and the second threshold value; determining the level of QoE of the user to be outside normal range indicating at least one problem affecting the QoE of the user more so than said minor issue when the compound parameter for the fixed-duration accumulation period of time is above the second threshold value; and displaying the level of the QoE of the user over the fixed-duration accumulation period of time in a graphical user interface of a monitoring equipment.
 2. The method defined in claim 1, wherein the error check comprises a cyclic redundancy check.
 3. The method defined in claim 1, wherein the first parameter is received from the gateway.
 4. The method defined in claim 1, wherein the fixed-duration intervals have a duration of 1 second.
 5. The method defined in claim 1, wherein the fixed-duration intervals have a duration of less than 1 second.
 6. The method defined in claim 1, wherein the second parameter is received from the gateway.
 7. The method defined in claim 1, wherein determining the compound parameter comprises determining a difference between a first operand that comprises the first parameter and a second operand that comprises the second parameter.
 8. The method defined in claim 7, wherein the difference is an arithmetic difference.
 9. The method defined in claim 1, wherein determining the compound parameter comprises determining a quotient of a first operand that comprises the first parameter and a second operand that comprises the second parameter.
 10. The method of claim 1, wherein the appliance comprises a set-top box.
 11. The method of claim 1, wherein the media application comprises a TV application.
 12. The method of claim 1, wherein the gateway comprises a DSL modem.
 13. The method of claim 1, wherein the head end server comprises a D-server.
 14. The method of claim 1, further comprising: issuing an alert when said compound parameter exceeds at least one of the first threshold and the second threshold.
 15. The method of claim 1, wherein the level of QoE falling into a particular range of levels is displayed on the monitoring equipment using a unique color associated with the particular range of levels.
 16. A method of monitoring performance of a system that comprises a gateway connected to an appliance running a media application, wherein the downstream packets are received by the media application from a head-end server through the gateway, the method comprising: determining a first parameter indicative of a number of downstream packets that, within a fixed-duration accumulation period of time, have been detected as corrupted for failing an error check performed thereon at the gateway; determining a second parameter indicative of a count of severely errored intervals during the fixed-duration accumulation period of time, a severely errored interval being a fixed-duration interval, shorter than the fixed-duration accumulation period of time, containing more than a threshold number of downstream packets that are detected as corrupted at the gateway; determining, based on at least the first parameter and the second parameter, a compound parameter, for the fixed-duration period of time, indicative of an incidence of downstream packets having been corrupted during the fixed-duration accumulation period of time; determining a level of quality of experience (QoE) of a user of the appliance to be within a normal range when the compound parameter is below a first threshold value, the first threshold value being lower than a second threshold value; determining the level of QoE of the user to be outside normal range indicating a minor issue affecting the QoE of the user when the compound parameter is between the first threshold value and the second threshold value; determining the level of QoE of the user to be outside normal range indicating at least one problem affecting the QoE of the user more so than said minor issue when the compound parameter is above the second threshold value; and displaying the level of the QoE of the user over the fixed-duration period of time in a graphical user interface of a monitoring equipment.
 17. A method of monitoring performance of a system that comprises a gateway connected to an appliance running a media application, wherein downstream packets are received by the media application from a head-end server through the gateway, the method comprising: determining a first parameter indicative of a number of upstream packets sent from the gateway to an access network that, within a fixed-duration accumulation period of time, have been detected as corrupted for failing an error check performed thereon; determining a second parameter indicative of a count of fixed-duration intervals during the fixed-duration accumulation period, containing at least one upstream packet sent from the gateway that is detected as corrupted, the fixed-duration intervals being shorter than the fixed-duration accumulation period; determining, based on at least the first parameter and the second parameter, a compound parameter, for the fixed-duration period of time, indicative of a time taken to service an interactive command provided by a user of the media application during the fixed-duration accumulation period; determining a level of quality of experience (QoE) of a user of the appliance to be within a normal range when number of the compound parameter is below a first threshold value, the first threshold value being lower than a second threshold value; determining the level of QoE of the user to be outside normal range indicating a minor issue affecting the QoE of the user when the compound parameter is between the first threshold value and the second threshold value; determining the level of QoE of the user to be outside normal range indicating at least one problem affecting the QoE of the user more so than said minor issue when the compound parameter is above the second threshold value; and displaying the level of the QoE of the user over the fixed-duration period of time in a graphical user interface of a monitoring equipment. 